I know it's been posted before, but be VERY careful of where you donate. CNN is now warning about scams. The organization must be a reputable non-profit, not just some people collecting money. The reputable ones will have an internet presence, a mailing address, phone, and so on, and will probably be organizations you've already heard of. I also heard some good advice, which is to donate to organizations that already had a presence in Haiti, such as Doctors Without Borders. They had three hospitals there, but none are usable now. They have sent up hospital tents, and are continuing to work. . even though there has been loss-of-life among their staff. I'd put that organization very high on the donation list, if not at the top.
Also be careful of those who say they are collecting FOR other organizations. The donations can go directly to those organizations, not through a third-party.