Mac App Store
Smarts is a simple to use app that stores the criteria of your Smart Playlists the smarts of a Smart Playlist as templates so that you can restore them later, export for back-up, or share with other iTunes users.
Having a lot of Smart Playlists can slow iTunes down, but by storing your unused Smart Playlists as templates in Smarts you can then remove your unused Smart Playlists from iTunes and only reload them when you need them again.
What I've been using it for is to store "starter" Smart Playlists templates that contain frequently used criteria. Instead of having to re-enter a complex set of criteria every time I create a new Smart Playlist, I just load a starter with my basic criteria already entered and then I only have to add a minimum of new criteria.
WikiScoop is an app that allows you to browse Wikipedia using an index made up of the Artists in your iTunes library.
After finding an article for an Artist, you can bookmark that article to the Artist for faster retrieval later or offline reading. Additionally, you can set which Wikipedia language site to browse (currently English, French, German, Spanish, Italian, Dutch, Polish, Portuguese, and Russian).