I've also been monitoring the tsunami missing persons boards at the Thorn Tree forum on Lonely Planet's site. I've noticed a lot of people are trying to contact people that live and/or work on Ko Phi Phi.
This is a public service announcement: Based on an email we received last Wednesday from Maprao (our lodging on Ko Phi Phi), everyone on the island of Phi Phi has been evacuated to Phuket; this may explain why you are having trouble reaching folks by phone and most of them are swamped and behind in answering email. FYI, everyone at Maprao and their guests have now been accounted for and there were no deaths.
The Belgium-born owners of Maprao said they and others from Phi Phi have to stay in Phuket indefinitely - as the authorities are clearing out bodies and stabilizing the area first before allowing anyone that used to live and work on Phi Phi back. When I hear more news, I will update.