(the foot thongs people frequently kick-off and absent-mindedly put on their car roof while they go nature-walkabouts...).
I believe they are called "flip-flops" here in the states. When I used to back pack, I carried my film in the canisters in zip lock bags, inside strap on accessory bags. These are the soft pouches that attach to the main pack via the slotted leather patches. The ones I had also strapped onto my waist belt and I had a smaller one attached to a shoulder strap that held film for that day, and some other small essentials. I wish I could still go off on pack trips like I used to, 2-3 weeks in the Uintah Mts in NE Utah, or Sawtooths. My aging body cant do that anymore.