The Story of Stuff
This online video - also available for download (beware: it's 50mb!) - tackles the consequences of American hyper-consumption in a refreshingly irreverent manner.
Seriously, shut down your computer, unplug your iPod, turn off your PDA, cap your water bottle, take off your sunglasses, and learn how to make a difference. Don't worry - it's only 20 minutes long, so you can get back to texting shortly.