I'j just been having a play with The Filter. It's a rather neat addin to iTunes to automatically create playlists for you.
You select a few songs from your library the hit the F button. The Filter then creates you a playlist of songs that 'go with' the songs you had selected in iTunes. The results as you may expect are pretty skewed to genre but it does throw in the odd surprise.
I've been impressed enough to start using it regularly & find I'm listening to stuff I would have missed/forgotten about.
Oh yeah, it'll also pick up missing album art as it goes.
[Edit: Looks like it's from our favourite sledgehammer, Peter Gabriel.]