I have a Lowepro Computrekker Plus AW that will hold pretty much all my stuff, including my tripod and a 17" notebook PC. I decided to see what it would weigh with all that stuff loaded into it... 26.2 lbs without the notebook and tripod, and 40.4 lbs with. That's what I call "stupid heavy".
Luckily it is still very comfortable even with all that weight, but I don't think I'd want to haul it around all day. My problem is I can never decide what to leave behind.
Apparently I have too much time on my hands.
Edited figures... thanks to Doc F for the catch



