Biodiesel--Alternative Fuel of the Future?

Now that the US Military is getting behind it, will biodiesel become the first truly viable mass-consumer alternative fuel? Maybe not, but this biodiesel stuff sounds interesting. Especially the notion that all that leftover cooking oil from all the greasy spoons across America could have a better alternative for disposing of their cooking oil waste. Eat your fries and get a McFillup w/ the oil used to cook 'em.