You can do a conversion (my D80 is currently away being converted @ a cost of $325 US) They remove the IR cut shield from the cameras sensor and replace it with a small IR filter which means you can only shoot IR but you can use normal 'hand held' shutter speeds etc.
This was shot with a Nikon D70 (the best DSLR for infrared) and a lense mounted IR filter - these filters are a very dense red and cut out most of the normal light spectrum and just allow the IR rays through. This means you have to tripod mount and use long shutter speeds - you also have to focus/compose your shot prior to mounting the filter as its so dense you cant really see through it properly. Altogether its a bit fiddley but the results can be stunning
(you also have to do a lot of postwork on these images in the colour mixer etc)