I read about this site in a magazine article yesterday:
http://freerice.com/
For every word you match with its definition, the UN World Food program donates 20 grains of rice to countries in need. So 20 grains isn't very much, but if you get very into it, your vocabulary prowess will help the program donate a decent amount.
There is really no "end" to the game, so you can decide when to stop. Chris and I played for around 30 minutes and ended up with about 8,000 grains. We didn't "cheat" (aka "google") either!
I say NO googling, but then again, for every word you get right, the donation does goes up.