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

I use my fleece jacket for my pillow.  My sleeping bag comes with a little pocket at the head of the bag to stuff your clothes in to use for a pillow...or to stuff your pillow in if you must, I suppose.  Turns out the fleece jacket fits perfectly and does a pretty fair job of mimicking my pillow at home.

I used to use my life jacket but just never could get comfortable with it.  And when I switched to using clothes, that worked reasonably well early in the trip, but the later in the trip it got, the smellier they got.  By trip's end, it was usually back to using the lifejacket. 

But that heavy fleece jacket really does the trick and it's a double-duty item on cool-weather trips as well.  On hot trips, I bring it anyway 'cause with the weather up there, you just never know...

I received an Exped pillow for Christmas last year and I like it for when I’m on the ground.  Packs up to nothing and better than a stuff sack with clothes in it.

The problem is I have started to hang in a hammock and I find that I don’t need much of a pillow in the hammock.  I only put about a half a breath of air into the pillow then vs. two full ones when on the ground.