Don't have any advice to impart necessarily, but here's how I get around not drinking:
I'm severely allergic to alcohol, to the point where my face turns this scary shade of purple (not red) that immediately alarms anyone who looks at me. All my current friends know I don't drink but when I am with new people who ask "What are you having", I take that opportunity to joke about my purple face and occasionally throw in the story about how my mother tricked me into not drinking Coke for 20 years because she told me it kills brain cells... then that's my cue to order a Coke from the bar and give 'em a wink.
Works great for breaking the ice, and I've always found that having a drink is merely a type of signaling: that you aren't an unapproachable, stuck up, morally superior, I-art-better-than-thou type of person. So you just need to have other ways show that. I bet too that if you just focus on having a good time (instead of worrying about compensating for not drinking) the issue becomes irrelevant.