When I waited tables, I would always come to the table and say "Hi folks, my name is Widge and I'm going to be your waiter tonight. Can I start you off with some Richard Dawkins? I'll come back for your drink order once you agree with me that there is no god." I found it led to really great tips.
Seriously, I'm sure the account in that story never actually happened because nobody ever knows the religious affiliation of their waiter. I personally follow a don't ask don't tell policy on my atheism and I think most atheist do the same. In fact, when asked I usually just say I was raised Catholic and leave it at that unless pressed more on the issue.