Great (possibly biased, though) link. I'm definitely pro-biodiesel. I hope we can make enough of it without really causing the price of food to skyrocket. If the numbers in your link are right, it's a much better bet than ethanol.
I have run a few gallons of BioDiesel, both straight and as a mix with PetroDiesel. Seems to work fine except it solidifies in the winter. 20% biodiesel seems to be OK at 20 deg F so far. 40% is marginal and 60% & 80% are also frozen solid. (I have some sample mixtures in bottles on the back porch to check it out.)