The Exped Synmat Basic 7.
While it isnt the lightest pad in the world I have heard they are very comfy and REI has a smoking deal on them this week for $39.00! I ordered the long and wide which is 25x80.
Has anyone else used a synmat while hammocking, I purchased it because I am getting starting and will need the ability to go to ground if the wife comes hiking along with me. I figured the insulation factor should make it nice for hanging too, I nice multi-function piece of kit for a smoking deal, cant lose!