I never knew whether these creations were collages, montages, or something relatively new. The techniques for creating most of them were new, at least to me. Some involved the APG Gigaprint head, that could click at the same exact angle in 360 degrees. It was meant for creating Giga prints, i.e. you could easily stitch them together with a program for that purpose.
But instead of stitching 30 or more images together to create a panorama, or just a super large file; you could instead layer them vertically atop each other in Photomatix, and then decide what you wanted to show through the mess (with the ghosting tool).