CD Tracker

...and then, for my audio CD collection, there is CD-Tracker. I've been collecting CDs longer than I've been collecting video, and I have traded many, many audio CDs over the years. (I've even re-bought certain CDs a number of times when I've decided that I couldn't live without them. That's the kind of music fanatic that I am.) You can do the same thing with CD Tracker as you can with DVD Profiler, although CD Tracker does not go into as much detail in their listings as DVD Profiler does. However, both of these services are free, and I can live with some drawbacks when it's free!