Adrian Warnock points out that tsunami-relief donations from the British public have now exceeded the initial pledged aid from the British government. He wonders if such is the case in the US by now. A Google search has led me to believe that has happened.
So far as I can find, there are no totals from all private relief agencies in the States. But the magnitude of the private contributions that are known is pretty huge. Toledo Blade columnist Jack Kelly says that as of last Wednesday, contributions to seven US relief agencies totaled more than $34-million.
This article from the International Herald Tribune gives some totals for private giving around the world that are quite interesting.