I've been speaking with some other diesel drivers locally about trying to make BioDiesel an option for us. It can be ordered in gallon jugs, cases and 55 gallon drums through a half-dozen of so suppliers. If I recall, it's currently about $2.40 to $2.60 a gallon but it's not necessarily run full strength. It's usually run as an 80/20 (Bio/regular) blend with regular diesel so as not to require engine modifications - apparently the 'purer' forms of it degrade the rubber in the fuel lines - and I suppose to make it more economical. The 80/20 blend is available in a few markets, though not widely. Check out this web site for more info:
http://www.biodiesel.org/
Even at the 80/20 blend it burns cleaner (less particulates - an issue where I live) than diesel. Also supposedly has greater lubrocity (lubricity?). The straight form (no blend) apparently smells like french fries cooking (mmmmm, drool, french fries...). It's possible to use waste vegetable oil to make BioDiesel - a process called transesterization. An oversimplification is to say that it involves heat, lye and methyl alcohol, but people can and do make it on their own. You can get the 'recipe' online doing a simple search. I'd think that among this group of DIYer's there would be someone who is into 'making their own'!
SVO requires separate tanks and heating elements on the lines to make it flow. You start the car on regular diesel and then switch over to SVO when warmed up.
Don't try either alternate fuel in your gas cars - only diesels!