Usually when you give someone alcohol as a gift, it means you completely forgot the occasion and stopped by the liquor store on the way over. But for those that do plan ahead, Knob Creek offers personalized labels to add to the bottle. And it's available through the Knob Creek website year-round. Just fill out the label with a personal message and submit. Discretion is advised and Knob Creek states on the site that they "reserve the right to refuse printing of any inappropriate material," so don't get too crazy.
I first read about this at Drive-Thru where Jill states that shipping could take 4-6 weeks. I guess that means you have to really plan ahead.