Actually I probably should have said, there should be several examples in the main galleries before we consider making a gallery...
Several people have asked about a B&W gallery in the past, there are probably many more examples of that than there are of infra red but no gallery has been made. This is because photography is generally sorted by subject, rather than by the method/style of photography used. Whenever I think about how to "file" images, I try to imagine where someone who is new to the site would look for it. I think in most cases people have a scene in mind, for example, beach, horse, car, etc, so this to me is the best way to sort images.
Remember that you can use "tags" to help people find images as well, so you could always tag the images as infra red... look under the "community" link on the left for more info.
I agree, tags are useful. I agree with Samatar that new people would look for "subjects", but infrared is emerging as a separate category in the digital domain because it is being used much more digitally than it was in film photography. Many people aren't even aware that it is different and that converted cameras or special filters are used. So they wouldn't even know to search for it. Just food for thought.
If there was a way to have multiple categories for images, I think we would definitely have categories such as B&W, HDR, infrared etc. but the site doesn't have the ability to do that ATM. (other than by using tags, I mean)