Continuing Apple’s series of iCloud-related developer releases, reports suggest that Find My Mac has now officially gone live for developers at well.
The feature is turned on and off using the iCloud panel in System Preferences (you must have Lion 10.7.2 beta and the latest iCloud beta for Lion to do this), and is then accessed through the Find My iPhone pane on iCloud.com
Apple uses location data from whichever WiFi router you are connected to in order to determine your location, and it seems to be pretty accurate in its results. Using Find My Mac, you can remotely lock your Mac, perform a remote wipe, play a sound, or show a message.