Last.FM is a great site that takes information from your iTunes account and displays playcounts for artists and albums.
I would like to create some sort of app that takes the music statistics from a user’s “Last.FM” account a bit further and displays a range of new, different statistics, such as what percent of your music is female/male vocal-fronted, instrumental, genre, or what decade it’s from, and displays it in a visual way, like a pie chart, for each category. So, it would basically be a hack on your existing Last.FM statistics.
These new statistics could be based on existing tags from Last.FM, and could be an interesting autobiographical look at different aspects of a user’s listening habits less common than simply “most played artist” or “most played song.”