I always camp semi-primitive, ususally using my ENO Doulenest, Bug Guardian, and a Tarp, plus whatever I build. If I'm doing survival practice, no hammock. But Tarps rule. They are, after all, one of the 5 "C"s of Survivability, "Cover". I have lots of tarps. Mostly cheap ones, a few heavy duty ones. a couple sil-ny, a few Grabber all weather blankets (hooded and un hooded), etc. Then I usually have at least 2 55 gal drum liners as well in my light kits.
Since you brought up tarps...I was JUST talking about this yesterday in the Pathfinder R&D group. Tyvek. It's awesome. It's very light, very tough. I actually want to buy a sewing machine so I can experiment with it. You can get the 9' wide rolls of 150' for $150, or buy it by the foot from people on ebay for about $1.50 a foot. a 9x6 would make a great shelter tarp. I want to sew the edges over and reinforce them, add drawstring loops, reinforced grommets, etc. Though you don't NEED all that. You could just put some Gorilla Tape in the corners and bunch it up and make a paracord/bankline tie off, or maybe grommet it with a kit. You get a very tough, very light, water proof shelter. OR, at the very least, a very tough, light ground liner. This stuff has lots of applications, limited only to your creativity.
One other note on tarps....One of my favorite tricks I learned from the pathfinder school is using 36" flat bungee cords to set up tarps for shelter over cordage. You can set them up REALLY fast, easily adjust it, and it gives it plently of play in case of wind or stress. I have 2 sets of 4 in my kit, thinking of adding another because it works THAT well. If you need to set up shelter FAST, a bungee set is the way to go. Try it.
[video=youtube;D_TZxMhIe9M]http://www.youtube.com/watch?v=D_TZxMhIe9M[/video]
Tarps in action:
This one didn't work out so well once it started raining...needed more side coverage...
And, to keep Moose happy, here is a picture with a Becker in it I just found in my photobucket account (was looking for this!)
EDIT TO ADD: Did a quick youtube search for someone using Tyvek, and came up with this:
[video=youtube;77f6NSAg4ag]http://www.youtube.com/watch?v=77f6NSAg4ag[/video]