I took apart my G2 and removed the IR filter and replaced it with a filter which does the opposite, block visible light. On a Canon 20d, yes you can but it will be more work. First thing you'll need is a Hoya Infrared filter for your lens. You'll be able to get the similar photo look, but because your camera(all digital) has a filter which blocks IR light to start with, it will require a longer exposure. so even in daylight you'll have to use a slower shutter. shot in AV or Manual mode, and do an exposure comp of -1 - -2. otherwise it may be over exposed. Canon does have an Infrared version of the 20d called the 20Da. It's made for astronamy which requires alot of IR light. hard to find this camera but it is out there.
A few places out there can also modify your 20d. But after the mod, you won't be able to shot color photos in the same way.
you seem to know a lot about cameras. I'm currently using hp707 but in the future I want to get a more professional tool. What can you recommend that isn't too expensive ?
The canon rebel series of digital slr is a great start. invest your money in lens, you can always reuse them on future cameras. Camera bodies depreciate but lens don't.
The next up from canon are the 50d which is alot of camera. the nice thing is the camera is much brighter view finder. that's why I upgraded from the rebel series.
Thanks for the advice I'll keep in mind about the lenses but I've already bought a nikon d60. So far I find it pretty good but I don't have anything to compare with.
how did U do it? can I do it to my Canon 20D?