Have you heard the one about the algae-fueled jet?
No, it isn't a joke. Earlier this month Continental did a 90 minute test flight with a Boeing 737 using a 50-50 blend of bio fuel and normal aircraft fuel. It seemingly went well. You can read the full article for details on the interesting process.
The airline industry has been testing alternative fuels (good idea!) This was the first such test for a US airline. Bravo!