I just donated 25$ to the Red Cross because of the Katrina debacle. I don't think 25$ is a lot, but I think that if a grad student living from a stipend can afford 25$ then affluent Americans can afford to donate a few more dollars. The funds will add up, I have faith in multiplication.
It's not like I'm simply giving away my money, I'm investing in America. I know there will be a time when some other part of America (perhaps the part where I reside) will require help, and I hope a similar mentality will drive some other graduate student on the other side of the US to donate his 25$ (and perhaps help me eat).
My friend Mark recently put up this http://robogradshelp.blogspot.com/ for robograds to donate to the Red Cross. This site is merely a gateway to the official Red Cross site. So far we have a few 1st year robograds who donated 25$.