A friend recommended this site:
http://www.freerice.com/index.php
It's a neat idea, you define a word from a list of 4 choices (and it matches your vocabulary level after a few times, so it's a good challenge) and every word you define correctly, they donate 10 grains of rice through the UN World Food Program. How? Because the advertisers at the bottom of the page pay for it.
So come on you English majors, earn that food