If you want to help out, one thing that I've seen mentioned a few times from a few sources I trust (and they all seem to have confirmed this directly), is to text HAITI to 90999 to donate $10 to the Red Cross relief fund. The donations add up quick, so it really can help.
To donate more than $10 or to find other ways to help, I'd head over to www.redcross.org for other options.
Update: It looks like the donations are definitely working already. They've raised over $800,000 at last count. That's pretty incredible I think.
Edited by Atnevon, 13 January 2010 - 06:56 PM.