As always happens with current events and especially with relief and aid efforts, scammers come out of their holes to steal money meant for the unfortunate. E-mails and social networking messages will start pouring in and fake relief websites have popped up already. Avoid scams that only make scammers richer and donate only directly to major organizations (such as the Red Cross) or at least do your research first.
The Better Business Bureau has a listing of charities that are in good standing at http://www.bbb.org/us/charity/
For more information about the scams, see the Ars Technica article on the subject.