Always a fun topic!
I'm no Les Stroud, but I've watched him on TV!
I always carry one of Doug Ritter's Pocket Survival Paks:
With that, you get a compass, whistle, signalling mirror, fire lighting kit, and a whole bunch of other useful stuff in a small enough package that it easily fits in your pocket.
I wear my PLB around my neck inside my jacket.
Not to sound like an ad for Mr. Ritter, I also always carry one of his folding RSK knives.
In addition, I stuff the following in my pockets:
2 Bic Lighters
1 Fire steel
1 zip loc bag with Vaseline-soaked cotton balls for fire starting (If I can't make a fire with all that...)
1 Heet Sheet survival blanket per person (Works against rain, sun or cold. Also makes a decent signaling device)
I carry a bunch of other stuff (strobe light, backup hand held GPS, sleeping bag, water filter etc.) but obviously not on my person.
I'd like to wear some sort of vest with all this stuff in it, rather than stuffing my pockets, but haven't found the right one yet...
"It's such a fine line between stupid and clever. " — David St. Hubbins