more people than i thought do it, but you're right its not out there in the masses and i'm kind of glad, there's enough competition for used cooking as it is lol.
i think it is not for the faint of heart, you are basically using old cooking oil (that usually stinks), Methanol and caustic (both are truly awful chemicals) to create fuel to put in your pride and joy. yeah, come to think of it, what the hell am i doing haha.
I've been doing this for around 3 years, its a hobby, great for the environment and saves me dosh!