Free rice

Freerice.com

Do you have a few minutes free in your day to play an online game?  Freerice is an educational quiz game that donates 10 grains of rice for every question you get right.  The rice is donated to the World Food Programme to help end world hunger.

"In its first six months of operation, Freerice donated over 42 billion grains of rice. One month after ..., users had earned enough points for one billion grains of rice. The United Nation's World Food Programme stated that this amount could feed 50,000 people for one day,  since it takes 400 grams or about 19,200 grains of rice to feed one adult for a day.  Using this calculation, enough rice was donated in 2008 to feed over 6,000 people daily for each day of that year.  Since its inception, as of October 15, 2010, Freerice players had earned sufficient rice to feed over 4.32 million people for one day." ~ Wikipedia.