Basically an online vocabulary test, much like the SAT, it presents you with a series of multiple choice definitions. Your answer to each question is scored immediately and you move on to the next one. (You can set options so that when you leave your computer the site "remembers" your score for the next time.) The site automatically adjusts to your vocabulary level. When you get a word wrong, the next word provided is from an easier level. When you get three consecutive words right, you move to a higher degree of difficulty. (Experts say that this constant fine-tuning of levels is the best way to ensure you are learning and not just playing a game.) FreeRice has 50 levels in total, but staff say it's rare for people to get past level 48. Go ahead; knock yourself out. But you're probably wondering about the site's odd name. And therein lies the best news of all. Each time you get a word right, the site's sponsors donate enough money to pay for 20 grains of rice for the United Nations' World Food Program. That may sound like a pitifully small amount, but the site has already raised more than five billion grains of rice in less than two months.