iTunes version 8 sets out to impress, delivers
Perhaps the most-hyped iTunes addition has been the new Genius feature, which is actually two closely-related new features: Genius Playlist and the Genius Sidebar. The Genius features rely on sharing of your music library information with Apple’s servers–anonymously, Apple hastens to add.
The first time you launch iTunes 8, the software invites you to set up the Genius feature–a process that involves signing into the iTunes Store, agreeing to the terms of service, and sitting back and waiting while the software gathers information about your music library. How long this data-gathering takes depends on the size of your music collection. With my 30GB library, the setup took about 10 minutes. Macworld contributor Kirk McElhearn has a library that tops 200GB; he reports that this step took more than an hour. (Not that this will tie up your computer–you can play music, listen to podcasts, browse the iTunes Store, and do other things with iTunes while Genius gathers its information and sends it off to the iTunes Store to be processed.)