I've used Cardstore for Christmas cards for many years now. They print postcards, which we love -- photo on one side, personalized text on the other. No long Christmas letter to write but still an opportunity to let loved ones know what we've been up to, and less postage. Best of all, Cardstore mails the cards for us. Easy peasy.
This year, Cardstore has a new product that I'm loving: Photo Gift Tags. They also have Photo Business Cards, which are not holiday specific but are the same dimensions as the gift tags.
Here's a sneak peek at one of the gift tags I just ordered: