My friend Oliver, who is always on the leading edge of fun technology, showed me an iTunes Genius playlist on our drive out to Costco last week, and I had to try it as soon as I got home and put the 8 lbs of salmon in my freezer. There are a number of music recommendation services, like pandora.com that find and recommend songs you might like based on music you do like (Pandora does this by assigning "genes" to various aspects of a song (lead singer, type of background vocals, distortion level) — up to 500 characteristics, and uses about 150 of them to recommend similarly appealing music). But the iTunes Genius playlist is a little different not just in the way it operates (though unconfirmed, it seems that Apple is comparing preference data from millions of iTunes store and Genius playlist users worldwide), but in what it produces: Genius creates playlists from your existing iTunes music library, in addition to using a sidebar to make recommendations of music you might like from the iTunes store. If you're like me, you've accumulated lots of tracks you never listen to, because you haven't had the time to add them to a playlist. Now iTunes does that for you, exposing tracks you might really like, based on the ones you do. Have songs you really like to relax or exercise to? Particular tracks that inspire romance or creativity? Just select them in iTunes, hit the Genius button, and instantly create a playlist of your existing music based on that song. Genius indeed.