This is a GREAT idea as I spend a ton of time online doing nothing. At least this time someone will benefit from my mindless surfing.
I found this site on treehugger.com, which might I add I LOVE and read on a daily basis. Anyway I was breezing thru and happened upon this article for FreeRice.
Basically all you do is match the correct word with the definition. For each word you get right they donate 10 grains of rice thru the United Nations World Food Program.
I played it and actually knew a lot of the words! I played for about 4 min. and earned 300 grains of rice. I do have to wonder who exactly counts these grains of rice, but whoever does it bless their counting mind!
Try it!!! Its fun and keeping your brain sharp is important too!!!