Even though we fully acknowledge our unusual paranoia about anything involving, we think normal people may benefit from something like this too.
The "Bag Snatcher Alarm" might be worth the $72 investment if you've ever had a momentary panic attack when separated from your luggage at a terminal counter or hotel lobby, however briefly. The concept is simple: You attach a signal transmitter to your suitcase or bag, then affix the receiver to your keychain, clothing or forehead. If the two devices are ever separated by more than 2 to 5 meters, the receiver will emit a loud beep. (Just pray that there aren't any trigger-happy security guards in the immediate vicinity.)
For items that you're willing to let stray more than a few feet away--like whining kids--you may want to consider the "."