Houston, The City of Infinite Possibilities

 If  Houston were an independent nation, it would rank as the world's 30th largest economy, 23 Fortune 500 companies are headquartered in Houston

Wal-Mart Inc. topped the list as the top revenue-grosser with $421,849 million in revenue and $16,389 million in profit in 2010.

Houston metro area companies on the Fortune magazine list include (in reverse order):

• El Paso (No. 481 in the country)
• Spectra Energy (441)
• Targa Resources (416)
• Group 1 Automotive
• Frontier Oil (389)
• EOG Resources (377)
• Cameron International (375)
• Calpine (349)
• Enbridge Energy Partners (309)
• Kinder Morgan (294)
• Centerpoint Energy (279)
• KBR (242), Anadarko Petroleum (223)
• Apache (206), National Oilwell Varco (202)
• Waste Management (196)
• Baker Hughes (170)
• Halliburton (144)
• Plains All American Pipeline (99)
• Enterprise Products Partners (80)
• Sysco (67)
• Marathon Oil (29)
• ConocoPhillips (four).

Two energy companies with major Houston presence — ExxonMobil and Chevron — recorded profits this year that far outdid those of top revenue-earner Wal-Mart. ExxonMobil nearly doubled Wal-Mart's profits, taking in $30,460 million in profits. Still, it ranked second overall on the list.

The Houston area had 25 companies on last year's Fortune 500 list. Continental Airlines — which is no longer based in Houston — is one of the ones that fell off (since it has merged with United and is now based in Chicago). The other? CVR Energy, which ranked 472nd on Fortune's last list