Freerice.com

With the price of rice doubled over the past two years, rice is increasingly becoming scarce. The poor from all around the world are again at the brink of starvation.

There is this website www.freerice.com. They have a word game for you to play, and for every correct answer that you make, they will donate some rice to the poor. I don't know how genuine the donation part is, but the word game part is not too bad. It tests your English vocabulary, pretty good for someone like me whose mother-tongue is not English.