There is still dew to contend with, unless you can camp right under a tree. There are also such things as mosquitoes. In my case, I insist on a bug-free space for my dog as well as for me, which is why I use a tent.
A lightweight breathable (DWR top) bivy--the kind many recommend for use under a tarp to repel splash when it rains--might be your best option. It should keep the dew from wetting your sleeping bag. You can get them with mosquito netting. Since they have waterproof bottoms, you won't need a ground sheet. The Titanium Goat Ptarmigan bivy is one example.
Edited by OregonMouse (11/10/09 03:39 PM)
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey