I always tried (manually..) to keep my iTunes library organized, including cover images, album names and genres...
Via lifehacker I recently found Pollux - a neat and free (!) application which analyses given songs and fetches all required metadata from the internet. Version 1.1.2 did not work great, since the new version 1.1.5 it's perfect...
If you work on a mac, go get it here... (don't forget to donate if you like it!)
Update (Oct 2009): Pollux has been such an overhelming success that they cannot handle requests any longer... hope they'll be back online soon!)
Update again (March-Mai 2010): They are live again - better than ever. Great tool, way better than all the other crap I tested...
