[mythrwy]

I was in Guatemala in the early 90's on a bus and it stopped near a stand with people selling soda.

The procedure was open the soda bottle, pour the soda into a plastic bag, put a straw in the bag and tie it. The vendor kept the bottle (presumably you could keep the bottle yourself if you paid the deposit with your soda). I kept waiting to see a bag leak or some other disaster but it seemed to mostly work. You couldn't put your soda down though. Maybe it was a scheme to encourage rapid consumption or accidental loss and sell more sodas, not sure.