Google just dropped a bomb on the official Android blog moments ago: Android Device Manager, a tool to help locate your lost phone. It's simple - you can track your phone from a web interface (or the official Android app!), and then ring or wipe it. Simple? Yes. Absolutely something we've all wanted since, I don't know, ever on Android as a standard feature? Duh.
Android device manager will be part of - you guessed it - Google Play [Services].