I've been reading some about time banks, and tried out Timerepublik recnetly..Haven't made any deals yet, but I figured I'd talk about them anyway.
http://www.technocracyinc.org/time-banks/So it's just a system where everyone records how much time other people spend doing things for them, and that counts as credits they can sue to ask for other people to do stuff. This seems pretty useful in a setting where you have a lot of people doing miscelanious stuff (sketching, writing, coding, producing music) but not neccisarily a lot of coordination. I figure it'd be nice in that it could fill in a space between doing open requests and regular comissions, where you've got some assurance that people are putting rougly about as much time into doing things for the community as other people are spending to do stuff for them.