For two hours on a Friday night, caroling groups fan out across a ten-block radius of downtown and sing in front of shops, restaurants and hotels, while passersby vote for their favorites. The top three groups then return to Pioneer Courthouse Square for a final carol-off. It's the 12th year of Portland's version, free to watch, and a fun way to wander downtown in December with a hot drink in hand. Choirs, office teams and ugly-sweater crews can register to compete.