LoJAck
I like the "erase data" and locator features advertised with Lojack but I have been lead to believe it's relatively simple to circumvent the application.
A quick read of MACs firmware password sounds good as a general stop gap but is it stable and how much trouble can I cause by screwing up the activation?
MAC Pro Desktop MACbook Pro 13", Mac OS X (10.6.2), 2.8ghz 6g ram / 2.5ghz 4g ram