The War Houndz discuss gaming for charity. Streaming for causes, and helping with game studios trying to raise money for charities.
Please, make sure that whoever you donate to is a reputable source and will actually donate to the charity and not make a profit.
A couple of good charities: www.ablegamers.com www.dedicatedservers.com
Humble bundle is having a sale right now with 10 great games and part of it is donated to charity: www.humblebundle.com
Dedicated servers is hosting a 24 hour Gears of war stream for breast cancer awareness, details here: http://dedicatedserverscharity.com/?p=298