Would you recommend a groundsheet?

[OneClick]

I cut up a small piece of green utility tarp. About 16" x 32".

Nearly paper thin and can fit anywhere in your pack folded. 1.45oz. It's a no-brainer for me.

In a pinch you could use it as a wind break on the tarp or around your stove. Also a nice large clean area to sit on.

[murphyw]

Tyvek is my personal favorite, but all my thru hiker friends chide me for not using the polycryo as it is almost 1/2 the weight.

http://gossamergear.com/polycryo-gro...th-medium.html

[ADKrella]

I use a small sheet of plastic to set my pack on.
Ive also used a contractor's clean up bag when I knew it would rain to put ALL my stuff in it...but thats kinda a overkill
When I was using a sleeping bag instead of a TQ it was nice to be able to stand on something to get in the bag and zip it up before I got in my hammock too.

[Nickhob]

Tyvek is my personal favorite, but all my thru hiker friends chide me for not using the polycryo as it is almost 1/2 the weight.

http://gossamergear.com/polycryo-gro...th-medium.html

+1
I use a 16"x16" piece of tyvek, just to have a place to put my feet down when I get out/up. I tried the polycryo as it is indeed lighter, but after a bit with the junk it picks up off the ground etc... it gets sticky and as it's so thin it can become a bit like glad wrap and a real pain in the *** to unfold.

[Shiner35]

I have a piece of plastic that came with a Coleman tent I have it was designed for this very thing.