Let's hope whoever came up with the brilliantly simple concept behind FreeRice never abuses the gift of marketing smartness because I can see how this site could become addictive. Consider yourself warned.

It's essentially just a multiple choice vocabulary game that adjusts to your performance, increasing in difficulty after 3 correct responses in a row, knocking you back down after every wrong answer. But here's the thing: for every word you get right, 10 grains for rice are donated to the United Nations World Food Program. That added up to a meager 830 grains on the first day, but just one month later, the daily count was up to 77,126,310, the total to 1,008,771,910. That's a lot of rice!

The site is supported through unobtrusive ads from some very big companies, including Apple, Macy's, and American Express.

Form and function so rarely agree to this extent. Go have some fun, learn a few new words, and contribute to ending world hunger today. And tomorrow. And probably the day after that.