According to Charity Watch
http://www.charitywatch.org/toprated.html
the Red Cross gets an A+ for their effecient use of their money. If you have an account at http://www.amazon.com
they will take your donation to the American Red Cross--it goes to tsunami relief.
Here is USAID's list of charities with links working in the area.
http://www.usaid.gov/locations/asia_near_east/tsunami/ngolist.html