If we had something like this for those dance machines in the arcades, our lives would be so much better. The Potion Factory team has finished with version 1.0 of their music arrangement app for the Mac, known as Tangerine!

Tangerine!, now with the exclamation point, is an iTunes plug-in that automatically arranges your music based on the beats per minute (BPM) of the songs. Unlike arrangement by genre, this lets you make playlists that the app deems to be moving with a certain beat, so if you want to go jogging with a quick beat, you might find everything from electronica to "Tunak Tunak Tun" on your final playlist . (A Daler Mehndi classic, by the way... - ed.)

Unlike the free beta versions, however, the latest version is now neither in beta testing nor free. It's currently priced at US$ 24.95, so only serious beatmasters may want to apply. You'll also need to use Mac OS X 10.4 to run the plug-in. Still, if you've got a hankering to figure out which songs move as fast as "Total Eclipse of the Heart," then this would be the app for you.