For anyone who wants to help but doesn't know how, _samalander has made an excellent post on ways you can help out--even if you have no money to spare.

Click here to see the amazing list she's compiled

If you, like me, aren't able to donate blood due to health reasons, please check out help_japan as well as local church/news stations. I know several local groups near me are running phone banks and they need volunteers. Even if you can't give your own money, you can help someone who can give their's. Alternatively, take some time out of your day to send some positive thoughts (or prayers, if you are so inclined) towards those in need.