When I came across this site, I was stunned. In short, you play a vocabulary game to earn rice for donation to the poor. Here is their “How to Play” instructions:

1) Click on the answer that best defines the word.
2) If you get it right, you get a harder word. If wrong, you get an easier word.
3) For each word you get right, we donate 20 grains of rice to the United Nations World Food Program.

This game can really test your vocabulary, and at the same time you get to donate rice. What an idea!