I have traded a few CDs on lala.com, cleaning out discs we don't really listen to, and receiving music that we like. It is a pretty clever system. You list the CDs that you own and the CDs that you would like and the system will let you know if anyone wants your stuff. You send off your CDs in the prepaid CD mailers, and pay a small fee when you receive one of your requests. My husband and I had some duplicate CDs in our collections, so those provide good trading fodder.