Amazing article that my friend showed me earlier, although it looks a little dangerous. http://lifehacker.com/software/diy/turn ... 287252.php
Perhaps one day, when I'm getting a new computer.. Love those articles about how to make your own "whatever" on instructables. Too bad I'm way too lazy to actually try one of them myself
the scary thing is that you can use an infrared diode which is invisible to the human eye. so essentially you can be burning someone across the room (assuming you give it some length by using a special type of collimating lens) and they wouldn't know why they were getting burnt.
I wouldn't worry about that, there's lots of descriptions on how to make your own 10$ infrared goggles on the site as well