I am totally anal when I rip a CD onto my computer — I input the song title, artist, and album name as accurately as I can because when typos and lowercase text come up on my iPod, it makes me insane. When I get files from someone else who is not quite as OCD as me, I painstakingly try to fix any misspellings. I hate a disorganized-looking iTunes!
FixTunes had me in mind — it corrects your mp3 file names so that you don't have to look at something ugly, AND with the correct spelling, FixTunes gets you the right album art!
After downloading (Macs and Windows both welcome), you'll notice several FixTunes playlists in iTunes — when you go into the "Not Looked Up" playlist, you can select any song, and the FixTunes window will display the probable match. Click "Fix" and voila!
Now what else can the internets help my neuroses with . . . ?