I have just donated to a charity called Feed the Children. I gave a mere pittance it would seem, but my wife and I also give regularly to that charity.
Feed the Children is a Christian program that helps children in poor countries, and also in the United States when catastrophes like Katrina happen (no offense to all those ladies named Katrina out there).
You can donate to them, or you can go to the Truth Laid Bear, who has enlisted almost 1000 bloggers to drum up support for a large variety of charities and support organizations. Feed the Children and World Vision are among them.
I should also link to Glenn Reynolds roundup post where he lists more places to send your money than I even have time to read.