There’s nothing better than a little old fashioned spying. The Under-Door Remote Viewing kit slips under most 1/4″ doors and provides a 55 degree view (left and right) of the hidden action within a 15 degree line of site (think tunnel vision). Optional accessories include an infrared attachment and video camera mount for recording all the would be terrorist or insurgent activity.
No word on price or availability, but you can submit a request for more info here.
Complete spec here (warning, it’s a PDF).