When a song is playing in iTunes, they show arrows next to the song name, artist, and album name as seen below. The normal behavior for these arrows is that when click on them, they perform a search in the iTunes music store for the song/artist/album based on which arrow you select.

The search arrows in iTunes

When I am listening to the party shuffle in iTunes, I'll often hear a song and think, "hey... I'd really like to listen to that album." The lack of this functionality is one of my biggest pet peeves with iTunes. Wouldn't it be great if, instead of sending me over to the iTunes music store, clicking the arrows performed the search in my iTunes music library. That way I could easily get to the entire album I am listening to, or to all the songs by the given artist.

If you are on a Mac, you can make this happen pretty easily. Just open up a terminal window and type the following:

defaults write com.apple.iTunes invertStoreLinks -bool YES

If iTunes is open, you need to close it before this change takes effect. Now clicking on the arrows performs the search on your iTunes music library. This is sooooooo much better. If you really find that you to perform the search on the iTunes music store instead of your own music, you can re-run the command and change the YES to a NO.