In this case you could make the OS on the internal hard drive to do "interesting" things if somebody ever happens to boot it, like:
* Log anything the user does (URLs, passwords etc), take photos with the webcam
* Scan for WLAN networks & connect to network
* If that fails, use few dollar/euro prepaid SIM to do cellular connection instead
* "Call home" to log close-by WLAN & phone base stations etc info needed to locate the laptop and identify its thief
* If "Home" tells that the device should do something, first disable volume & power off keys
* Then start blinking the screen & blasting from the tinny speakers something like "I'm stolen, please call police" etc.
Whoever steals that device, will probably remember it for a while and maybe even avoid geek conferences in future...