One of the interesting side effects of last year's stimulus bill was $400 million in funding for ARPA-E, the civilian, energy-focused cousin of DARPA. And in this week's first ever ARPA-E conference, MIT chemist Dan Nocera showed how well he put that stimulus money to use by highlighting his new photosynthetic process. Using a special catalyst, the process splits water into oxygen and hydrogen fuel efficiently enough to power a home using only sunlight and a bottle of water.