Saw a couple interesting things in the Sahalie catalog that came today. #1 - fleece fingerless gloves. Sort of like the wristees folks have been making, but with a little more thumb coverage. $10/$8 for 2 or more.
#2 - Toasty seat - NASA developed material, seat warmer. 16X12, folds to 4X12, 8 oz. $29.95. Not sure if it would work in a hammock, but looks interesting.