We're not germophobes here at Gizmodo—not necessarily because we aren't afraid of tiny sickness-inducing attack—but because we're too lazy to dust let alone sterilize. But the Germ Guardian Air Sanitizer offers a lifestyle of sloth paranoia we could live with. Using UV-C rays (like similar models on the market), the device kills 99.9% of airborne germs with light alone. Why do we like it? The Germ Guardian's design induces feelings of an inescapable bleak future—like it's waiting for us to curse, at which point it will blind us with a flash of light and we'll boil in our skin. Now that's a conversation piece. $200 [product via appliancist]
As a physican, I can tell you that the device is useless, other than to scare people, as you say (and make money)
1) Only a tiny fraction of the bacteria in a room is in the air, most of it sits on surfaces and in dust, or on our bodies, waiting to be blown up, shed, or rubbed off.
2) We rarely get infections from air. Even the pathogens that are "airborne" (e.g. flu) are usually BRIEFLY airborne (after a cough, etc.) then they fall to the ground where you touch the surface, pick your nose, and bingo...
3) At 18 inches tall (according to the manual), no way that thing even cycles a good fraction of the air in a room, unless its 50 mph fan and 150 dB loud.(of course if it did move air fast enough to cycle the room air properly, the air would be moving too fast for that pitiful 9 watt UV bulb to kill the bacteria)
4) I think I'll buy the white one. The white one is prettiest, don't you think?