Learn Something New at iTunes U

If knowledge is power, get ready to level up. iTunes U, a new section in the iTunes Store, offers lectures, presentations, videos, and other college-level coursework, all of it free to download. Duke, MIT, Stanford, and UC Berkeley are among the dozen-plus universities currently offering content, which includes such business-oriented titles as "Managing Risk in an Uncertain World" (Stanford) and "How to Attract Customers by Giving Them the Short End of the Stick" (Duke).

You'll need iTunes, of course, though you don't necessarily need an iPod to play the downloads on the run. The files are unprotected, and most are provided in widely compatible MP3 or MP4 format.