I’m going to be a photo mule. My Lowepro Fastpack 250 camera bag, when empty, weighs 3.6 lbs. Add my Canon 40D and 3 lenses, and the total weight exceeds 9 lbs. On top of that, add the HP dv2’s 4 lbs (incl. a 6-cell battery) and I’m lugging around 13+ lbs on my back! And that’s *before* I add a water bottle. Fraaaak!
I have a bad back on top of a screwy right knee. Long hikes into the wilderness carrying my camera gear will probably kill me.
My advice to all you folks: Don’t grow old.