(internet+sensors)
sawa project http://dev.hci.uma.pt/sawa/main/login
wiki http://dev.hci.uma.pt/mediawiki/index.php
Share sensor data | set policies | record data | sms, email notifications and much more
you can extend it, creating your notification plugins...


(gps+gsm) open gps tracker http://www.opengpstracker.org/
nice project for locating stolen equipment

Software is nice, but formatting the disk makes all software protections/sytems goes away. Using a GPS/GSM module with SIM card, inside the laptop (for example internal PCI) is a better way to locate stolen laptops and other devices. In opengpstracker the "system" even sends you a SMS when the hardware is moving at certain velocity. Also you can SMS for GPS location, or las know GPS location.