Something you don't see in the U.S.

Glass cola bottles.

I remember, during grade school, getting 25 cent Coke bottles from the teachers' lounge after basketball practice, and they were a relic back then. I can't imagine any place distributing them now.

But many Korean restaurants use them even now. Since they don't have soda fountains, there's not really such a thing as "free refills." Typically, two people will share a bottle, and order more as needed.