There are a number of ways to create playlists in iTunes including handpicking your favourite tracks or relying on the Genius feature to sort things out for you. Moodagent is a little different in that it can produce playlists that suit your mood.
The Moodagent web site features a huge database of tracks which have been profiled in a variety of ways. Your own music collection can be synched and compared with the profile database - this can be done via your iPhone or on your computer.
You can then use a simple slider system to indicate your mood, and Moodagent with choose a series of tracks that are deemed most suitable. Playlists are created in a matter of seconds and can be saved for easy playback at a later date.
Moodagent can also be used to create song based playlists - using this method you can pick your favourite track and generate a playlist built around similar songs. The app is a joy to use and may help to you to find part of your music collection you had completely forgotten about.