Coincidentally, the Feb. issue of Shutterbug has an article about digital IR. There was also an interesting footnote about a company that actually offers a hardware option by modifying older digital cameras to become dedicated IR cameras:
"One company, IRDigital, actually converts certain digital cameras to shoot black and white IR. This option is for serious IR shooters only though, as the conversion is a one-way trip (the camera can’t be returned to its original state), and the converted camera can only shoot black and white IR. The modification is currently available for the Canon EOS D30, D60, 1D, and Digital Rebel (300D), as well as the Nikon D100. To locate one of these older camera models, try Shutterbug ads or eBay. Conversions cost $350 for all except the Digital Rebel, which is $500. See
www.irdigital.net for more details and examples of landscape and portrait subjects."