Apple has recently released Find My Mac.It has only been released to developers. The Find My Mac service was officially added to Lion in Developer Preview 4.
Find My Mac is very similar to Find My iPhone. This is because they basically kind-of do the same thing.
One downside is that Macs do not have GPS inside them so it relies on Wi-Fi.
Once it finds the lost Mac, users can send a message, remotely lock the screen, or even wipe out the entire drive. Find My Mac will probably be released this fall with the general release of iCloud. The release of iCloud will probably be very close to, if not the same day as iOS 5.