Getting the oil ready for the car does seem like a pain, I got this email from a biodieseler...

"I get my oil from 3 sources now. My first (and main) source is the
cafeteria here at hte university where I work. The other two are
privately owned hamburger joints. All 3 are happy to give me the oil
for free. I've provided them with wide-mouth containers to make it
easier. The only consumables (other than the oil itself) are the
filters. I just bought 10 3-micron filters for $3.81 each. I
pre-filter the oil through old blue jeans! When the jeans fill up
with crud, I just squeeze it out, and stick them back into service.
Squeezing them out is fairly messy, and I need to streamline that -- I
only started experimenting with that within the last month. The oil
that comes out of the jeans *looks* clear, and the jeans fill up with
"peanut butter" which I either burn in the wood stove or throw away.
I then let the oil settle for about a week, then I heat it, let it
settle for another day or so, then I filter it through 2 of the
3-micron filters. With the oil prepared in this way, I can get
upwards of 100 gallons through the filters. So that would say that my
oil is costing me overall about 7 1/2 cents a gallon."

But ****, 7.5 cents a gallon for a guy that's getting 125 mpg. Holy cow!!!