The Brazilians claim to have invented the flip-flop, and whether that's true or not, they certainly enjoy wearing them. Flip-flops are acceptable street wear for men and women of all ages in Copacabana, befitting the beach vibe.
The original and still ubiquitous Brazilian flip-flop brand is Havaianas, which has become more popular in the States of late – and is also one of Brazil's great shopping bargains. They cost about half what they cost back home, and with a much wider variety of styles and colors.
There's a Havaianas store every few blocks in Copacabana with walls of flip-flops, including several styles of official Rio 2016 flip-flops, which at about $10 American make for an affordable and easily packable souvenir to bring home.
Luke DeCock: 919-829-8947, email@example.com, @LukeDeCock