I just learned about a cool new website called freerice.com that made me feel smart and charitable.
You play a vocabulary game and for every right answer you give, the site donates 20 grains of rice to help end world hunger through the United Nations World Food Program (WFP).
WikiAnswers tells us that there are approximately 7,200 grains of rice in a cup so as the site keeps track of the number of grains of rice you'll be donating by the number of words you get right, you can also figure out how many cups of rice that'll make. 
You can choose to have the site remember you and the level you reach every time you play by selecting the "options" link at the top of the page and setting the options to remember your vocabulary level and donation total on your computer."
I got up to Level 43 this morning (and donated 400 grains in about 5 minutes), but got knocked back because I missed "cognate" which I'm sure isn't even a real word. I don't know if Level 43 is high or not, but I'm going to assume it's lofty ...vertiginous ...eminent ... and probably at the pinnacle ... zenith ... apex.
Is it just me who thinks playing a vocabulary game is wicked fun? My family won't play Scattergories with me anymore so this feeds my passion. You can play for as long as you want, which is good because it does get addictive.
I actually found out about this on snopes.com so am confident it's true, and I checked out the freerice FAQs, and was even more interested. The rice is paid for by the advertisers on the site, but the ads aren't overwhelming. It doesn't require registration or a password or nothing and it makes you feel smart because if you miss a word, it gives you an easier one. Here's the link to snopes.com in case you have doubts:
www.snopes.com/inboxer/charity/freerice.asp