If you haven't yet heard about my new app,Muud.io, here's a little bit about it:
Muud.io is a music app for iPhone & iPod touch that can recommend playlists, based on a given mood.
Simply pick a mood, and we'll build a playlist for you, using the music you love.
You can view a demo video (desktop-only for now) and screenshots over atthe Muud.io site.
Muud.io is available on the App Store (and is currently on sale at half-price for a limited time).