LaLa

LaLa is a CD club where you create on list of CDs you have that you don't want, and a list of ones you want but don't have. You browse the database and pay $1 per CD. The thing that makes LaLa stand out is that they give the artist 20% of the sale. Here's what one of the founders, Bill Nguyen, says:
"I'll be the first to advocate that artists should make a lot more from each CD. 'la la' is taking the unprecedented action of giving artists 20% of our revenues from used CDs, no used record store or online site does this today. I'll also promise to work tirelessly to reduce overhead in marketing costs across the industry, so artists can make more from selling their music.

I ask you to do your part by doing the right thing: remove songs from your iPod or PC if you've agreed to send the CD to another member.

If you want to listen to that CD again, just add it to your Want List and help us support that artist you can't get enough of. You'll have access to plenty of good music to enjoy in the meantime. We'll make sure of that!

Respect the artists and Karma will be on your side."

It's pretty cool. http://www.lala.com