I meant to post this site up awhile ago but never got around to it so I forgot all about it until today when I heard a report about it on npr.
the site is www.freerice.com
basically, you go to the site and and they give you a word and a list of options for definitions for the word. as you answer more questions correctly, the difficulty level of the word goes up. nothing new, right? well, here's where the revolutionary part comes in. for every word you get right, the site donates 10 grains of rice to help end world hunger. as the word difficulty goes up, the more grains of rice they donate per correct word. how can they afford to do this? they have sponsors that pay for ads on their site which they in turn use to pay for the rice. just yesterday alone they donated 167,077,300 grains of rice. so, if you have time, stop by their site, build your vocab, feed a hungry kid.