Having to run a whole heap of utes is a bit of a pain with high fuel prices. So I've been playing with the idea of making my own bio diesel. Apparently to do this legally you get taxed to the hilt.
Couple of sites of interest:
How to make Biodiesel and driver test
BioDiesel Forum http://www.biofuelsforum.com/using_biodiesel/
BIODIESEL EXCISE EXEMPTION REFORM
go here and help lobby the government to get an exemption
Overall seems like a fairly simple process will have to see if the raw material (used oil) is easy to get a hold of in a fairly continues supply