In EDC a mylar blanket and an orange poncho.

In BOV (I use a vest, rather than a bag) an 8x10 Siltarp, a couple hundred feet of paracord and a foldup saw big enough to cut wood to build a real shelter.

In car kit a North Face 2 man tent, and a large plastic tarp.

Attached to my BOB is a 2 man tent. My BOB is rather extreme and it also weighs about 55 lbs. Yes the tent adds weight, but I am able to walk all day with it on and with the tent, I will be able sleep warm, protected from the element and I will, like CK stated at the bottom of this post, have a place to think and regroup. I also carry a 8x8 tarp and tie downs, 100 ft of 550 paracord and 2 ratchet tie downs. I have my reasons for carrying all this. As I have said before, I can and have carried my pack all day in the mountains of Wyoming. The tarp is an extended part of my shelter. The winds in WYO can blow up to 80mph (45 mph today), and the tarp can be wind protection (or a sail when you are trying to set it up). All in all shelter is an important part of my BOB. I have a 7 year old and a wife that I have a resposibility for and I am more willing to do uphold my responsibility if the wife and kid are less cranky by being warm and rested. Just a thought.

Pocket
Disposable poncho

Belt Kit
Silnylon poncho
6x8 Silnylon Tarp
AMK Heatsheet

Fanny Pack PSK
2 AMK Heatsheets
10x10 Silnylon tarp
AMK Bivi