Google’s recently release Android device tracker, allows to locate your android device, give a ring and erase the contents of your phone from a web interface. According to a some groups in case of a hack to the severs may leave almost all users of android device manager traceable.
CyanogenMod’s upcoming service is a bit different. Instead of sending the information through the server, your browser instead sends a public key. The phone authenticates the public key and sends an encrypted key back. The server cannot decrypt this key; only the browser can. This establishes a secure connection that cannot be decrypted on the server side, even if someone manages to get hold of that data. Using this connection, you can track or wipe your device.
The service is not out yet, but will be eventually. The source code has been fully published, and the CyanogenMod devs encourage people to check the security and safety of the service.