Get Bill Gates to talk about our biggest problems. At Microsoft one theme stands out for me - Go big or go home. Now Bill Gates is doing the same for Charity. And with his departure the profile of his Foundation grows. Check out his site - http://www.thegatesnotes.com/Default.aspx. I especially like the infrequent question section.
And if you think you have nothing to offer because well your a geek like me. Think again. Find a cause and go help. Charities just like any organization needs technology. Technology helps organizations be productive and charities tend to have low resources and could use your help.