Music collections tend to vary from mp3 collections. I personally own a lot of CDs that I don’t plan to import to iTunes… currently I don’t have enough hard drive space. I get kind of annoyed by people who no longer buy CDs because they can illegally download them for free, but I also don’t want to be a victim of the greedy music/recording industry. Still, it is very important to support your favorite artists because most of them only get a small portion of what their albums make. I think they make more from concerts and merchandise, so that is also a good way to support them.
There’s also Soundflavor though I actually don’t use it.