With iTunes 8, Apple released the new iTunes Genius into the wild. It can display music that's similar to the song you're currently listening to as well as create playlists based on a "seed" song that you choose.

Unfortunately, it seems the system so far is based only on the music available in the iTunes Music store, which limits the usefulness a lot. In addition to that, iTunes takes the liberty of sending data about your complete iTunes library to Apple. I'm sure they are receiving a lot of data through data, and are creating a very interesting database... They might even use it for music marketing, I guess.

Leider basiert das System wohl nur auf der Musik, die im iTunes Music Store erhältlich ist. Damit ist die Nützlichkeit doch sehr eingeschränkt. Außerdem nimmt sich iTunes die Freiheit, Daten zur kompletten iTunes-Bibliothek an Apple zu schicken. Apple kriegt dadurch einiges an Daten und baut sicherlich eine sehr interessante Datenbank damit auf...

I quickly tried out the features, but they don't seem to work very well with the music I'm listening to. I guess I will stay a last.fm user.