I've seen some folks here with BOBs that must weigh forty to fifty pounds (as mine used to be when I started many years ago).
I came to realize there's no way I'm going to carry forty plus pounds on my back, plus body armor, plus a long gun, handgun and ammo, plus misc other gear, and be good for more than about 100 yards between breaks / naps / pain killers.
Multiple big knives? Multiple multi-tools? Sharpening stones? Kitchen sinks? A library of big, fat, heavy books? Big, heavy flashlights (MagLights)? What are some folks thinking? It's a recipe for failure.
Lightweight is the name of the game. Spartan. Keep things simple.
This is a great thread and I've picked up a couple of ideas on improving my gear.
Here's what I had in my pack, with photos, from the Meet and Greet thread I did on an event that I hosted in Urbana, IL about a month ago
http://thesurvivalpodcast.com/forum/index.php?topic=18673.0. There's still room for improvement, but what I've got is pretty refined and certainly lightweight - at just over 20 pounds (which is about 10 more than I'd like).

The bag itself, a medium ALICE pack with a genuine USGI folding shovel and canteen, along with some 550 cord.
In the inside pocket are food products, including a single MRE, a couple of Mountain House entrees and some oatmeal and hot chocolate. In the flap is some cash, USB drive with personal inventory and documents, etc., paper, pens, deck of cards, etc.

Inside:
Most all in freezer bags... towel, TP/napkins, leather work gloves and synthetic cap, socks (including wool) and polypro underwear, feminine stuff (pads and tampons), First Need water filter, a set of BDUs (probably to be soon replaced by 5.11s, a tarp with reflective inside coating for shelter or blanket, personal hygiene items (soap, baby wipes, shampoo, bug juice, sunscreen, etc.), some freezer bags, a wood saw and several "construction clean-up" ultra heavy duty black plastic bags.

In the pockets
550 cord, meds, contact solution, toothpaste & brush, mirror, hydrocortisone cream.
Miniature FRS radio, Fenix CREE 1-AA LED with multiple settings and spare batteries. (There's supposed to be a tiny AM/FM earbud radio in there...)
Heavy twine, Gerber multipliers, fuel tabs, candles, waterproof matches, bic lighter, etc.
IBD bandage
Combat tourniquet.
Nitrile gloves.
First aid products - pads, gauze rolls, band-aids, tape, CPR microshield, etc. 2 emergency rain ponchos.
Surveyor tape, aluminum tent stakes, clips for tarp, compass, cup, Esbit stove and fuel blocks, space blankets (2) and a space blanket sleeping bag.