Adam
I started looking into Biodiesel production and after 2 years I finely started. I kicked myself for not starting earlier as it is piss easy and it doesn't have to cost much either.
If you have not checked out this site yet have a look it is by far the best I have seen.
http://www.biodieselcommunity.org/index.php
The bloke in the house behind us has a Diesel Rangey with a 6litre TurboChev...