People ask me how they can help. Right now, most help we can give is remotely--even for me in Japan. This is a link to a list of organizations, vetted by the University of Washington, who can accept your donations, but please consider not earmarking your donation, e.g., to a large agency which may well be able to use the money elsewhere when Japan's needs are met.
If I come across more specific ways people can help, I will let you know. For one small example, we in the tsunami-science community have been organizing some people who can help translate and edit updates and information from our over-worked colleagues here in Japan.
Right now, I am aware that one of the best things I can do for these Japanese colleagues is to deflect unnecessary contacts with them. This includes me not bothering them, too. If you have specific questions about the tsunami and its predecessors and aftermath, I can try to answer them here [and see prior posts] or direct you to the many experts who can. Here is a list of University of Washington experts who can answer questions -- despite the title, it's been updated and now also includes experts on nuclear engineering: