If you're skimming the Web to burn through a few minutes (Travelocity, anyone?), you'll love this site, which combines vocabulary quizzing with real, genuine donations.
It's called Free Rice - http://www.freerice.com/ - and for each word that you correctly guess the meaning to, they'll donate 20 grains of rice to help end world hunger. Legit? It is. Parntered with the UN World Food Program, Free Rice is a sister site to http://www.poverty.com/. Yesterday, wordsmiths the world-wide racked up 120,839,820 grains for donation.
Got a minute? Stop searching for great, green travel deals and join in the fun here.