The technical name for this fine specimen of a bag is: A.L.I.C.E. That is, All-Purpose Lightweight Individual Carrying Equipment. Leave it to the U.S. Military to come up with a cool acronym for something with an unnecessarily long name.
I got my A.L.I.C.E pack as a Christmas gift when I was 10, and used it to play "army" with my pals from around the block. This thing is original Vietnam-era Military Surplus, though. It deserved a more dignified fate.
Now that I'm older, and my G.I. Joe phase is long behind me, I use my A.L.I.C.E pack as a go-to travel companion. It's light, spacious and extremely convenient to travel with. And let's face it, could tech gear get any cooler than this?? The main compartment is the perfect size to fit camera gear and other odds and ends. If I need easy access to something, I slip it in one of the frontal pouches that snap shut.
Sure, I might be the only one in the airport carrying a 1969 military issue rucksack... But isn't it better that way?
By the way... they're really cheap too! Look for yourself!