I took a look - very very nice.  This site kicks ass over all the other trading sites!
I like the unlimited free trading.  They have a free subscription that lets you catalog and organize your collection of CDs, videos, and games.  The paid subscription - (fairly cheap at $20) gives you unlimited trading, and they send you 5 envelopes.
They have a great wish list feature that lets you list what you want, and they will email you when it becomes available.
Cool ability to watch other people`s collections.  This is nice when I want to watch for my friends collections, and when they buy new music, or games I get a message, so  I can go borrow theirs...(then I don`t have to buy it.) 

   (I`m cheap)
I also really liked their visitor logs.  Tells me when someone is checking me out.
I wish they used the same database as iTunes.  At the bottom of the page, it says they are using  Muze, and a lot of independent bands are missing.  They say they will have the ability to add CDs to their database but that can be a pain.
Here is their link:
http://www.sonicswap.com