In the spectrum of alternative fuel sources, biofuel made from algae is perhaps the most easily mocked. How could the slimy green muck that grows in your aquarium and washes up on the beach be a future cornerstone of American energy independence? So when President Obama stood before the University of Miami recently and said algae could provide up to 17 percent of our transportation fuel, we wanted to know: Is he right? Here's what we found out: