"SantaCon brings a new sense of humor and community to downtown Portland. It's a chance to meet people, take oneself a little less seriously and celebrate the season," she said.
In Japan, revelers offer Yuletide charity with Santa litter-picking outings.
In 2005 in London a SantaCon do-gooder paid off parking tickets, according to Reuters.
Drivers found this note on their windshields: "Don't let this ticket spoil your Christmas. Here's £30 to pay it off. Merry Christmas, Parking Ticket Santa."
In Texas this weekend, Austin photographer Hopson will be part of that city's Santa Rampage, shooting portraits of the wildly costumed participants.
The first year, in 2002, about 75 revelers turned out, but last year saw more than 500.
Hopson dresses professionally in a red vest, carrying North Pole press credentials.
"Austin, being the weird place that it is -- our folks make costumes more imaginative than in other places," he told ABCNews.com. "We have pirates, squid Santas and lots of elves."
They dress not only as Santas, but Hanukkah Harriet, reindeer, Christmas trees and fruit cakes.
"We expect a huge mob this year, mostly young adults," said Hopson.
"It's essentially nothing but a pub crawl, and we actually meet, have dinner and go to the entertainment district with hundreds of clubs," he said. "The costumes are outrageous and some are rather suggestive. You have to be out on the street and get into it."
Some are not so into it.
Last year, the event turned raucous when a rogue group protested Austin's Santarchy, attacking the jolly icon for all the "harm he'd caused," said Hopson.
Christine Malik, a 42-year-old computer support specialist who goes by the name Piper Santa because she plays the flute, participates in both Austin's tamer daylight gathering and the raucous night crawl.
During the day, Santas go to shopping malls and ride on city buses, singing holiday carols. By night, they hit the bars and restaurants downtown to spread and imbibe in Christmas cheer.
"There are hundreds of us -- enough to cause a spectacle," she told ABCNews.com.
Or turn people off.
"Some people think that Santa will be too rowdy and not let him in," said Malik.
One upscale hotel in Austin banned them from using the hotel's grand staircase for a group photo last year.
"They said, 'We can't have a mob of Santas anymore," she said. "It's a security thing."
Indeed, some Santas are naughty, not nice.
In 2005, the Auckland, New Zealand SantaCon turned into a political protest against the commercialization of Christmas. Participants started a small riot, looting stores, throwing bottles at passing cars and assaulting security guards.
At least two bystanders were injured and three were arrested, according to the Web siteAllExperts.com.
But to most participants, that type of incident flies in the face of the real meaning of SantaCon, which is bringing joy to the world.
"The best part is the reaction of people when hundreds of Santas show up somewhere," said Malik. "First you have the surprise on their faces, and then it turns into smiling and laughing. That's what we do it for."