Just came across:
http://arduino.cc/forum/index.php/topic,54655.0/topicseen.html
Making scanning mechanics has a big advantage in sensitivity level over mirroring, that will work
on big area/distance.
I remember 've been watching a movie, something about a war in Iraq.
They use similar temp-cam on a helicopter to hunt bad boys in complete darkness of the night.
One pilot or even unmanned dron could control a small city or few sq. km of the desert....
The same time its not something advisable nowadays, reliability of moving part issue.