Learning for rice.
FreeRice.com lets you play a simple multiple choice vocabulary game and for every word you get correct, you donate 10 grains of rice to the UN. Each question gets harder and harder every time you get it right so bring out your dictionaries :D. It's just a fun way on clicking on ads because for every word you get, you get transported to another page with new ads. The ads pay for the rice. It's like The Hunger Site, only you can click as much as you want and it's great if you want to learn. The Hunger Site is more of my style though. Vocab quizzes get boring quickly but it's great if you have nothing to do at home. :D