got a cheap tarp for car camping years ago ( $8 maybe? ) that we have employed for the last 2 overnight rainy backpacking trips to great success. combined with our trekking poles to raise up the corners, we have a palace in there to eat, drink, cook, and read under without being confined to our tent until bedtime.
http://whiteblaze.net/forum/vbg/file...5/img_1255.jpg we like to set it up where theres a good rock or two underneath to sit on where possible. i dont know what it weighs but its so light i dont notice the difference carrying it except for its size profile but i just shove it in the mesh pocket on the outside of my pack. the only thing i want to do is get glow in the dark paracord for the guylines like my tent has.