A LOT OF READERS complain that the Amazon tsunami donation page sends money to the Red Cross. But a lot of their complaints are aimed at the ICRC -- the International Committee of the Red Cross -- and not the American Red Cross, a different organization, and the one that's actually getting the money. I donated to them, but if you're uncomfortable, there are lots of places you can give money to. What interested me most about the Amazon phenomenon was how quickly and dramatically it worked, raising lots of money without a lot of overhead.
Hugh Hewitt recommends WorldVision. I haven't ever donated money to them, and don't know a lot about them, but if Hugh is recommending them I'm sure they're okay. The Salvation Army -- which is generally regarded as especially efficient at getting relief money to actual recipients with low overhead -- is taking donations, too. And, as I've mentioned several times before, there's an absolutely huge list of places to donate at the South East Asia Earthquake and Tsunami Blog, though I can't vouch for most of these. There's also a big list at The Command Post.
As always, you should be careful about who you give money to. Most of these organizations are probably honest, but it's best to take a little effort to make sure that your money will really go where it's promised to.
UPDATE: Tim Blair emails:
I'm personally familiar with World Vision's work (via them we sponsor a Zimbabwean boy with the beautiful name of Obvious) and recommend World Vision without hesitation. Low overheads, lean, efficient, get things done. They're the opposite of the UN.