The Ugly Christmas Sweater Party, once just another way to describe family get-togethers around the holidays, is now a concept so popular that workplaces and newspapers hold contests. There’s even a Web site devoted to the intricacies of such an event. (Here’s a summary: Buy ugly Christmas sweater. Invite others to do the same and then come over for some beer.) And on eBay “ugly Christmas sweater” brings up thousands of hits.