tangerine

Here's a clever thing. Admittedly it's only a beta release at the moment, but it's called Tangerine and it helps you create playlists in iTunes. Specifically, it analyses "the BPM and beat intensity of the songs in your iTunes library", which means that it makes it easy to create playlists that are full of crazy beats for when you're off out for a run, or perhaps a more relaxed set of songs for when you're reclining by the pool. Smart.