The Akron Beacon-Journal carries a piece (Hat tip to Tripso Daily) on using your points to help Hurricane Katrina victims.
The best advice, no surprise, is to visit Webflyer.com which has a rundown of how to use your points to make a difference. Most major programs have a way to either donate points (which in many cases will be converted to cash for charity by the loyalty program) or to earn points for your own donation of cash.