Despite several copycat efforts in recent months, this is still the best place to buy music, legally, and it's more popular than ever, selling 2.7 million songs a week. Choose from more than 700,000 tracks or check out the new celebrity playlists (Mischa Barton is a Guns 'N Roses fan? Who knew?). Another new treat: music videos (a video link will appear on the artist's main page, if there are any in the offing). Before you can visit the store, though, you'll need the iTunes software, which is free and runs on both Macs and Windows PCs (Macs need OS X; PCs Windows 2000 or XP). Get it at apple.com/itunes/download.