A new feature in iCloud enables you to track your Mac via a web interface. Here’s what it looks like:

And here’s what it does— when you lock, it seemingly logs you out and reboots the machine (though if that’s normal, I don’t know— console reported it as a “crash”), into a new pane that looks like this:

And once you type in the code, it brings you to:

A login screen, with your user and “Guest User”.

The Guest User is a full screen Safari browser, which some people have speculated might also double as a honey-pot designed to convince would-be-thieves to connect to a network and therefore betray their location to a waiting iCloud user. I’m skeptical of that because they’d have to get past the locked code screen, but it’s not absurd.

Regardless, this is a big step forward for Mac OS X tracking— a product that catches up OS X by default to third party utilities like Prey Project.