I saw a guy portaging on Singing Brook portage with a pillow with his gear - "that's odd" I thought. 

It was one of those horseshoe kind that people use on airplanes.  didn't give it much thought, but seemed odd that it was not in a pack.  Then I guessed that he must be using it for additional padding on his portage yoke, which made sense and might work pretty well (I didn't actually see him using it).

either that, or his hemerhoids were acting up and he used it on his canoe seat - anyways, I guess it could double as a nighttime pillow