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.

optionsXpress (OXPS: 0.00 N/A)
OptionsXpress jumped 2.3% after CEO David Fisher joined Jim Cramer on Tuesday’s Mad Money program to talk about the increasing popularity of options trading. Ten years ago, only Wall Street insiders traded options, but these days it’s becoming increasingly popular for the individual investor as well. Mr. Fisher indicated that only 10% of options traders use his company, providing the company with a large untapped market potential.

XTO Energy (XTO: 0.00 N/A)
Mr. Cramer again was extolling the virtues of natural gas on Tuesday’s Mad Money show. Carbon emissions could be reduced by as much as 50% if natural gas was used in place of coal or oil. XTO Energy rose after technical analyst Bob Simpson lauded the company for selling 40% of next year’s output at $9 when current natural gas prices are only at $3. The stock finished up 2.3% today.

Cramer’s Lightning Round stock picks:

Potash (POT: 46.46 +1.02%) dropped 0.8% – Cramer remains convinced that the stock is a buy and will likely go back up.
Altria (MO: 28.84 +0.07%) rose 0.4% – Cramer likes Altria’s management and their unbelievable 7.4% dividend yield. “This stock has $20 all over it”, said Cramer.
Sprint-Nextel [[S]] fell 0.5% – Cramer doesn’t believe the stock will turn in a good quarter and wouldn’t recommend buying unless the stock dips below $3.
Peabody Energy (BTU: 36.82 -1.58%) fell 0.2% – Cramer provided a lukewarm recommendation of BTU saying that if you have to own a coal stock then Peabody Energy is the best of the lot.