As a general rule, I've been opposed to fuel sources made from food products... mostly because it diverts production from food at a time when people are starving around the world and food prices are soaring. But I don't object to biofuels in general, and that's why I'm excited by efforts to turn algae into diesel fuel.
Some strains of algae are ideal for fuel production because they produce higher concentrations of natural oils than other plants. Additionally, they don't take up land that could otherwise be used for growing crops, because algae grows on the water or in bioreactors. Oh yeah, and by using algae, we're not diverting food away from people (unless, of course, they're eating algae... ew).
Questions still remain about whether or not algae will be viable, both economically and environmentally. But either way, it's a lot better than using corn or soybeans.