Stumbled upon this one while browsing Gizmodo (from user comments, no less).
PreyBasically, it runs in the background, and 'wakes up' when you send a remote signal,
and can be used to pinpoint the location of the device its running on. It also allows you
to remotely lock down the device as well.
Its a lot like the
Wavesecure app I used when I had my Nokia E71.