Given the tremendous increase in Apple’s (AAPL: 476.68 +1.67%) stock price, many analysts are nowwondering if Apple stock has become expensive. However, others claim that AAPL shares are cheap based on the furious earnings growth experienced by the company.

Yesterday, Deutsche Bank (DB: 46.26 +3.17%) increased their earnings estimates and price target for Apple. Just a few months ago, they expected Apple $13 a share. Now with the release of iPhone 4 and the iPad, Apple is expected to earn $18 per share.

These earnings increases has resulted in Apple becoming an “accidently cheap stock” according to Mad Money host Jim Cramer. He believes that Wall Street analysts have consistently underestimated Apple. Piper Jaffray (PJC: 24.12 +1.26%) had originally estimated that Apple would only sell 900,000 iPads by June. S.C. Bernstein had estimated much higher, but still only predicted 2M iPad sales. Of course Apple just announced that they have already sold 3M iPads.

Cramer likes that fact that analysts are increasing their estimates for Apple, but thinks Deutsche Bank’s estimates may still be too low. Cramer predicts that the tech giant could earn $19 per share. That would mean that Apple only trades at a multiple of 14x earnings and could result in significant upside in the share price.

Over the last 6 months since Mr. Cramer unveiled his mobile internet index, the Dow Jones Industrial average has gained 1,000 points or 11%. The technology-focused Nasdaq index is up 12% in the same time frame. So how has the Mobile Internet Index performed?

Unfortunately, the last 6 months has to be considered a mild disappointment for the mobile internet index. The index as a whole is up 9.6% during that time, but has underperformed the 12% gain in the Nasdaq.

The Mobile Internet indexes performance has been weighed down by a couple of extremely poor performances. The worst performer in the index, Palm (PALM: 0.00 N/A), has lost over half its value in the last 6 months. Tessera Technologies (TSRA: 19.31 -1.18%) stock has fallen over 30%.

While the overall index performance has been disappointing, there have been some stellar individual stock performances. Sandisk (SNDK: 46.84 +2.03%) is up an amazing 65% over the last six months. Starent Networks (STAR: 0.00 N/A) shares have soared over 56% since last August. In fact, 14 out of the 21 stocks have posted 6 months gains with 12 of those 14 stocks delivering double digit gains.

The big names of the index, like Apple (AAPL: 476.68 +1.67%), Google (GOOG: 609.85 +0.51%) and Cisco Systems (CSCO: 20.43 +1.14%) have also outperformed the broader market indexes with Apple leading the way with a 21% gain.

Monday
• Cramer is expecting Apple (AAPL: 476.68 +1.67%) to report strong earnings, but he would sell the stock now because of their upcoming tablet PC release on Wednesday. Apple’s stock pattern has been to sell into new product releases and buy after the pullback.

Tuesday
• Corning (GLW: 13.75 0.00%) and EMC (EMC: 26.33 +0.69%) – will give investors an idea about tech demand.
• Nucor (NUE: 45.31 -0.04%) and U.S. Steel (X: 30.94 -2.31%) – will provide a view on where infrastructure spending is going.
• Johnson & Johnson (JNJ: 65.24 -0.03%) – Cramer is worried that regardless of their earnings report, Obama could hurt that stock with some proclamation about health care.

Wednesday
• Boeing (BA: 75.46 +0.94%) – will let us know when they will be able to ship their new Dreamliner aircraft.
• Caterpillar (CAT: 114.04 +0.20%) – will provide insight into demand in the Chinese market.

Thursday
• Cramer labeled Thursday as “the busiest earnings day of the year” and he believes that many bad investment decisions will be made simply because of the information overload. He recommends investors stay on the sidelines until the dust settles.
• 3M (MMM: 87.97 +0.09%) – will tell us about Asian demand.
• AT&T (T: 30.02 -0.07%) – will give us an update on the cell phone wars.
• Colgate Palmolive (CL: 91.47 -0.08%) and Proctor & Gamble (PG: 63.64 -0.09%) – will tell us who is selling more personal products. Cramer believes that Procter & Gamble is likely outperforming.
• Amazon (AMZN: 185.48 +0.70%) – Cramer believes the stock, which is up 150%, will take a hit. He recommends buying it Friday on a decline.

Here is a review of the performance of Jim Cramer’s key stock picks from Friday’s Mad Money show.

Goldman Sachs
Goldman Sachs (GS: 116.15 +0.15%) stock gained 0.6% today after Cramer forecasted “pain” for the stock in the near term. Cramer believes the financial giant is a great company, but would steer clear of the stock as long President Obama is targeting the Wall Street firm.

Healthcare stocks
Humana (HUM: 85.15 -1.18%) fell 2.8% after Cramer put the healthcare stock, along with United Health Group (UNH: 52.14 +0.21%) and RehabCare Group (RHB: 0.00 N/A), on the sell block. Cramer acknowledged that the easy money has already been made in these stocks after the huge rallies off their 2009-lows.

Apple
Apple’s stock jumped 2.7% ahead of their quarterly earnings report. Jim Cramer advised investors to start selling the stock now ahead of Wednesday’s release of their much-anticipated tablet pc.

After the close, Apple’s stock was down slightly despite reported blockbuster earnings with revenues jumping 32% over last year.

Cramer’s Lightning Round stock picks:

• Linn Energy(LINE: 36.43 -0.87%) dropped 1.9% – Although Cramer has recommended this stock in the past, he doesn’t recommend buying after the stock’s big rally.

• Huntington Bancshares (HBAN: 6.05 +2.02%) gained 2.4% – Cramer advised investors to look at HBAN since the stock is “roaring”.

• Webster Financial (WBS: 23.17 +1.36%) jumped 6.6% – Cramer prefers this bank stock as they have few bad loans on their books.

Here is a review of the performance of Jim Cramer’s key stock picks from Monday’s Mad Money show.

Westport Innovations (WPRT: 40.27 +0.73%)
Westport Innovations shares soared 8.6% fueled by the “Cramer Effect”. Cramer advised investors that the best way to play natural gas is to invest in a company that is developing technologies to utilize natural gas. Westport Innovations fits that bill and Cramer feels the company has tremendous potential given their low market penetration. Currently, only 15% of WPRT’s sales come from North America. Increasing adoption of natural gas in the U.S. could push this stock much higher. “The underlying long-term story here could be incredible,” said Cramer.

Baker Hughes (BHI: 49.91 -2.19%)
Baker Hughes jumped 5.9% after Cramer warned that the global economic recovery would lead to increased oil consumption. This will lead to much higher oil prices and potentially even gas shortages. Obviously this would be great news of Baker Hughes as well as other major oil companies such as Marathon Oil (MRO: 32.69 -1.42%), Chevron (CVX: 106.76 -0.07%) and Weatherford International (WFT: 17.90 +0.62%).

Boeing (BA: 75.46 +0.94%)
Shares in Boeing gained 3.3% on Tuesday after Cramer remarked that “2010 will be the year for Boeing”.

Cramer’s Lightning Round stock picks:

• Akamai Technologies (AKAM: 34.44 +2.35%) gained 3.0% – Cramer called Akamai a “high quality play on the internet tsunami.”

• Citigroup (C: 34.23 +3.51%) jumped 3.8% – While not without risk, Cramer likes the stock and told investors that Citi is a “speculative situation that we like very much.”

• Apple (AAPL: 476.68 +1.67%) inched up 0.2% – Cramer remains Apple’s biggest fan and told investors that he stands by his $300 price target and believes AAPL could go even higher.

Here is a review of the performance of Jim Cramer’s stock picks from Tuesday’s Mad Money show.

Apple (AAPL: 476.68 +1.67%)
Apple’s stock soared 3.8% after Jim Cramer announced yesterday that he is increasing his price target from $200 to $264. Cramer believes that Wall Street’s earnings estimates are too low for Apple and believes the consensus estimates could climb from $8 to $12 per share. This will largely be the result of the expected changed in FASB regulations on how Apple can recognize revenue. Currently, revenue from new iPhone subscribers is spread over the 24 month contract period instead of being recognized up front. While Cramer believes that this could cause earnings estimates to increase dramatically, he believes the stock will maintain its current earnings multiple. That would drive Apple’s stock price considerably higher and he urged investors to get in now ahead of the announcement.

Flextronics (FLEX: 6.94 -0.43%)
Flextronics stock jumped 7.8% today after Technical Analyst Dan Fitzpatrick showed that the stock had already crossed its 50 day moving average and was ready for a breakout. Mr. Cramer likes the company for its fundamentals and diverse geographic exposure. Cramer believes that Flextronics is the cheapest stock in its sector and trades at only 12 times 2011 earnings estimates. While the stock has surged over 250% off its market lows, Cramer believes there is still more upside ahead.

Cramer’s Lightning Round stock picks:

First Solar (FSLR: 45.81 -1.67%) spiked 4.9% – Cramer continues to recommend First Solar as the only solar stock to buy.

Priceline (PCLN: 538.37 +1.73%) jumped 3.2% – Cramer called Priceline the Amazon.com of travel and believes the company has a strong business model and that the stock is only going higher.

Canadian Solar (CSIQ: 4.12 +11.05%) rose 5.0% – Despite bearish comments by Cramer who stated that he was nervous about solar stocks in general.

Movado (MOV: 18.99 +1.23%) jumped 2.8% – Another stock that Cramer was bearish on due to its position within the high-end market.

Duoyan Global Water (DGW: 0.00 N/A) a Chinese stock that many had probably never heard of before Thursday night’s Mad Money show, gained a whopping 8.6% on Friday. In the Lightning Round segment Cramer stated, “It is a Chinese water company, the answer to a lot of people’s prayers is to try to find some play on water.” However, Cramer didn’t want to embrace DGW despite being a big believer in China. Nevertheless, the mere mention of the stock seemed to put it on the radar screen for many investors. 

Mylan (MYL: 22.89 +1.60%) gain 3.3% despite the fact that Cramer said he preferred Teva Pharmaceuticals (TEVA: 44.94 +0.29%) over Mylan. “You know, it has been a hot stock. If you are going to be in there, I like Teva Pharmaceutical Industries Ltd.” Teva’s stock finished virtually unchaged. 

Finally, Palm (PALM: 0.00 N/A) gained 2.2% on Friday even though Cramer recommended selling the stock and taking profits. A month ago Cramer was very bullish on Palm ahead of the release of the Pre phone, but with rumors of high return rates and low sales volumes Cramer would be selling the stock now. 

Other Cramer bullish stock picks: 

Google (GOOOG: 0.00 N/A) gained 2.1% – Cramer is bullish on tech stocks because these companies keep coming out with new products and don’t need any bailout money.

Aruba Networks (ARUN: 23.55 -1.96%) rose 1.6% – “It is a buy, buy, buy… it is a little $7, $8 stock… I think that it goes higher.”

Apple (AAPL: 476.68 +1.67%) jumped 1.4% – Cramer is clearly a strong fan of Apple and he believes it is the most “Washington-immune” tech stock and predicts the stock will reach $200.

Huntington Bancshares (HBAN: 6.05 +2.02%) received the biggest boost from the “Cramer Effect” as its shares jumped 6.7%. In the Lightning Round of Friday’s Mad Money show, Jim Cramer had reiterated his earlier recommendation of HBAN from early June. “Why aren’t you in Huntington Bancshares?” 

Cramer’s other bullish stock pick, ArcSight (ARST: 0.00 N/A) also performed quite well with shares rising 5.7%. Cramer recommended investors look at ArcSight following on the recent cyberattacks in Korea and the United States. Cramer believes that cyber security will be the next big trend and thinks ArcSight stands out because of its clean balance sheet, decent growth rate, and $91 million in cash. Although ArcSight trades at a relatively high earnings multiple, Cramer would pay twice the company’s growth rate for the stock, and the fact that earnings estimates are so low may be an indication of an upside surprise. 

Other Cramer bullish picks: 

NetApp (NTAP: 39.775 +0.93%) gained 4.3% – “Net App is a winner! I wanted them to get Data Domain, but now I don’t know how they stay independent. I think the quarter is better-than-expected.”

Sallie Mae (SLM: 15.76 -0.38%) up 4.4% – “Now that the stock has pulled back, I want you to pull the trigger again. I think Sallie Mae is a winner.”

Apple (AAPL: 476.68 +1.67%) jumped 4.4% – Cramer predicts Apple will report quarterly earnings that will “blow your socks off.”

Honeywell (AAPL: 476.68 +1.67%) gained 3.8% – Cramer would be a buyer of Honeywell which is down 23 points, but has an impressive 4% dividend yield.

Commscope (CTV: 0.00 N/A) rose 3.7% today after Cramer remarked on his Mad Money show that CTV will be a big beneficiary of wireless buildout in China and India and rated the stock a buy. In addition, Cramer predicts an earnings beat for CommScope because of demand in Asia and improving margins as the price of copper falls. 

Shares of Lincoln National (LNC: 24.39 +2.39%) rose 3.8% after Cramer admitted that he is confused as to why Lincoln National is getting “smashed” after it just raised capital. “Once they get the money, they’re out of the woods, so you shouldn’t be selling them!”

Goldman Sachs (GS: 116.15 +0.15%) gained 1.3% after Cramer noted that Goldman Sachs currently trades at a very low multiple and is cheap based on earnings. 

Finally, despite pumping Apple (AAPL: 476.68 +1.67%) again on his show yesterday, AAPL’s shares fell 2%. Evidently expectations for a rally following Steve Jobs return to work don’t appear to be materializing.