I use cj.it's free,but like most free scripts it steals.I don't use it like a normal cj site would.i mainly use it for the stats part of it.I do trade with it some.It has more features than most other free scripts do.
http://www.circlejerkpro.com/
You might try this too.I tried it but didn't care for it much
http://www.shavenferret.com
I am a cheap bastard and I haven't found a real good trade script yet.Most of the free scripts suck.If you decide to use either one of those be ready for it to steal some traffic.Usually 1%.
Hope this helped.
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Your tattooed messiah