[MW Forums]

Undercover 2, the theft recovery software for Mac OS X, now works in Leopard and sports dozens of other improvements. more

[cweber]

If you own a MacBook or MacBook Pro, heck even an iMac, you should get this little app. We had two MacBooks stolen from our locked office a few months ago, and from the logs of the security system we can pretty much guess who stole them. But we cannot prove it, and so the laptops remain lost. If Undercover had been installed, I am convinced we'd had them back within a week, and the culprits would have been apprehended.
Chastised and wiser, we bought a large number of Undercover licenses and now install them on all Macs except Mac Pro models.
Although I hope none of our Macs ever get stolen again, I cannot help but chuckle when I contemplate handing headshots taken with the iSight, logged IP addresses, and screen dumps to law enforcement. Take that, low lifers!

[pubb]

But to stop the thieving bugger from doing an Erase & Install, I also have to set a firmware password, which can be reset by anybody with an Apple service certification. Or who has a friend with Apple service certification. Or who has a long conversation with someone who has an Apple service certification.
Cable locks and basic common sense are more effective, though far less geeky.