After years of hearing about "what Jews do for December 25" from friends, Hubby and I took the plunge last year. Sure, Philocrites has written about the December 24 party scene for Jewish singles, but we'll leave that to a younger crowd, and enjoy being so, well, domesticated.
Last year, after a breakfast of stollen and some gift-giving, we lunched on Chinese food and took in a movie: the very gay and very Jewish The Producers. It was a lot of fun, and this year we're looking forward to Dreamgirls (still very gay) and a nosh at a Chinese restaurant with a complex Cold War rendezvous past. (Locals will know what I mean if I say we're going to Cleveland Park.)
Christian or not, Christmas can be very hard on singles and couples. There's a temptation to try to replicate large-family celebration patterns, but these are probably not sustainable in smaller settings, or a temptation to do nothing, which just invites depression. If you're still at a loose end, you might try this for yourself. Scare up some friends and get out of the house. If Chinese and a movie isn't your thing, how about sandwiches and frisbee? If a conventional church service isn't interesting, see if there's a chapel service at a nearby hospital or airport. (At least you know you won't be asked to join a committee.) Or you could do worse the get on the phone and reach out to people you've not spoken to in ages. Oh, and don't forget the eggrolls.