It's called beets and the idea is this: just throw new albums at it; they get tagged correctly (from MusicBrainz), copied into a directory structure you specify, and catalogged in an sqlite database. Let me know what you think: http://beets.radbox.org/
Alternatively, I can just turn on Pandora and it plays music I like. It's literally a one click solution.
It makes better playlists than I could if I spent 2 hours a day perfecting my own. It also goes out and finds new music that I haven't even heard yet, but because Pandora knows more about the music I like than I do, there's a pretty damn good chance it will be right.
In the time since I've started using Pandora I've discovered more new music that I like than I ever did when I was buying individual albums or songs off of iTunes or whatever. Not only that, but I actually buy more CDs because I've heard all the songs on Pandora and I can buy the CDs with confidence, rather than wonder whether I'm going to waste another $15 on crappy music. Although, I was mostly buying CDs to play in my car, but soon I'll be getting a Droid, and then I can just play Pandora directly in my car so CDs might get obsoleted.
We're still improving it, so if you have any feedback, shoot me an email.