http://www.childsplaycharity.org/

It's a worthy cause as noted in their mission statement:

Since 2003, over 100,000 gamers worldwide have banded together through Child’s Play, a community based charity grown and nurtured from the game culture and industry. Over 3.5 million dollars in donations of toys, games, books and cash for sick kids in children’s hospitals across North America and the world have been collected since our inception.

You can either donate money directly or click a hospital near you and see what is on their 'amazon wish list' and buy/send it to them directly. It operates like a gift registry, but not to snooty people getting married.. to sick kids!