My IR is not Integrated Resort Lah... but rather on photography. Digital Infra Red. I used to borrow my friend's Hoya R72 (a type of IR filter for lenses) and was a bit peeved by the needs to screw on the filter on and off to compose a shot. This is because once you have an IR filter on the lens, the whole viewfinder becomes literally dark. The exposure time is long also as the camera's sensor has a layer of IR filter just in front of it. Blocking all the IR lights.
As 2nd hand DSLR cameras are getting cheaper by the day (more new models come out, the cheaper the older ones hehe). I got myself another Sony A100 and mod it to become a dedicated IR camera. Got it today from my trusty camera technician and tried it just now. Too bad its at night, not really capturing the potential but the effects are quite interesting.
Here's a sample of night IR... check out the sky with some clouds. Normally you won't get them with normal cameras.
And to answer some questions on whether this camera can "see" thru clothes.... well, in theory its possible but I dun dare to try leh.... :P