DH and I are beer geeks, and I will often take a "toll" from his glass if it is full of something interesting. It's only one very small sip, barely enough to cover my tongue and definitely less than a swig. My thought is it it's not enough to even come close to putting alcohol in my bloodstream, then it's okay. One night DH pulled out a 750mL bottle of a very nice local nanobrew which I had not yet tried, and I couldn't resist. I took a 3oz tasting glass out of the cabinet and poured 2 fingers into it. I probably drank half an ounce over the course of two hours. Again, I don't think this could possibly hurt, given that even among groups of women who binge or drink excessively during pregnancy, the rate of FAS spectrum is still pretty low.
A recent article I saw on WebMD made the point that since there is no established lower limit which is "safe", and Americans as a culture tend to go to extremes, doctors adopted a policy of complete avoidance.
I tried a couple midwife practices, and told them both about my occasional sips. I got two different reactions. One said it was totally fine, the other just said "don;t tell me about that" with a wink that was somehow knowing and scolding at the same time.
It's your choice to make, but those are my two cents.