Imagine you're a thief in the night, and you've managed to break into a store full of covetable, saleable goods. Suddenly, you hear a whooshing sound--and within seconds, the air around you is nearly opaque! Either you've gone batty, or the store has wisely installed the FogShield. It connects to your existing alarm system and is triggered by motion or a door trip.

The site says the fog is harmless to living things and to electronics; it even has a "pleasant mint smell." And it goes away after 45 minutes without leaving residue. The machine is $4,200 and has to be installed by an alarm tech. Each "fog cartridge" holds enough water-and-glycol mixture for 15 fogs, at $299 a pop.

At first, I honestly couldn't fathom how fog could be a burglary deterrent, but check out the videos at the site. It's fast! And once the fog is deployed, so to speak, not only can't you see anything, but most likely you'd be scared out of your wits. I'd love to get one to test out.... "I'm not sure if Carol's in today. Her office is filled with fog." Sweet.