I used to use my down vest consistently as my pillow and that provided me with a reasonable amount of comfort.

However this year I thought I'd try using a dedicated pillow while camping and picked up the MEC Backpacking Pillow; at $12 and weighing 150g it was neither a big investment nor was it unreasonably large. Most importantly I found it worked great and provide more comfort than using my vest was able to.

It is small, light, and inexpensive and it is a welcome addition to my camping gear for the added comfort it provides.