And let's not forget that obscure 120 camera (the name has escaped me at the moment) that uses half-frame (cropped top and bottom) on the 6x6 track to give 24 3x4 exposures -- similar frame size to 127 half frame, but oriented sidewise on the 120 roll.

And if you can ever find one, a 6x23 will give 3 exposures on a 120 roll. I'm working on building a pair (for pinhole)...