In the latest Developer Preview of Lion, Apple has activated the new Find My Mac feature. Like Find My iPhone, Find My Mac allows users to locate their Macs from any web browser or iOS device. As noted by 9to5 Mac, the Find My Mac setup is available through the Mail, Contacts, and Calendars setting in System Preferences. Simply click "Allow" and your Mac is ready to be tracked.
Once enabled you can use any web browser or iOS device to track your Mac. When found you can choose to play a sound or send a message, remote lock the Mac, or remote wipe the Mac. Remote locking and wiping will prevent you from locating the Mac again however. The