iTunes U has been around for some time now offering up cool courses from schools around the country that you can download straight to your iPod Touch or iPhone. I don't know what took me so long, but I just took a few free courses on video editing over the past week and I gotta tell ya: it's pretty awesome.
I take public transportation every day to work, so being able to brush up on math, grammar, and even astronomy during my commute seems like time well spent. And you don't have to spend a dime, since all the courses are free. There's been quite a bit of content added since it launched last year, so tell me — have you taken any iTunes U courses yet?