Apparently it's possible to
modify a digital camera to take infrared photographs, by removing the infrared filter and replacing it with one that blocks out everything but infrared (made from material obtainable from photographic retailers). It's not recommended that you do this to any camera you'd mind destroying if the procedure fails, but if you are successful, you get something that takes photos like
these:
Maybe the best solution is to replace the IR filter with something that passes a large spectrum including IR (maybe not UV), and then add an IR filter to your lenses for normal photos. It'd be very nice to have a digital camera that had many channels all tuned to different wavelengths. As we get to serious megapixelage, there's less and less reason to use those CCD elements for resolution, and more and more reason to use them for things like postprocessable depth of field and colour.
Clearly that's not just IR; an IR-only photo would have no colour information.
Also: elegant example of how water vapour acts as a greenouse gas.