www.traffic-out.com was my favourite (must be a free site, or a TGP with with a below a certain % shave)
www.exitcoin.com
are two I would personally recommend.
There are lots others.
www.kanoodle.com if want some nice SE traffic, but they upped it to a minimum $0.05 a click. If you need a URL for a free $5 account with them, there is one on freenetpass and adultinsider I believe.
ZoiNk