I while ago I started putting together my own tracking package but never finished it because my tablet has not been stolen yet. The basic premise was: 1. upon connection to internet, retrieve a specific file from my webserver. the request may include nearby wifi router macs. 2. if the file retrieves ok, execute it this is very simple and means i can do the rest of the implementation later if needed. the webserver logs the ip address and router macs. the macs' location can be looked up (eg: on wigle.net). normally, my webserver will just fail the request. if i lose my tablet, i can place a suitable script on the server. an example script might set up a tunnel back to my pc so that i can ssh into the tablet and do gps logs, delete files, camera capture etc, even behind a firewall.