I’ve just made my own ghetto night vision scope. It’s not exactly pretty, but it works, and it cost me under $30. I’ve got a cheap infrared flashlight that I’ve attached to my scope, and a $10 infrared webcam looking down the scope. I can then monitor it all on my netbook.
It’s not portable at all, and it’s a bit clunky to get set up. But I’ve been happily sitting in my back yard the last few nights, with a card table for my laptop and beer, and scoping rats on the laptop using my homemade night vision. They have no idea what hit ’em.