Shouldn't even be an issue for those acting responsibly. I usually don't even drink on anything less than a 12 hour layover and sometimes (depending on the circumstances) even on longer ones (it frequently screws up my sleep). Don't get me wrong, I like a glass or two of cold Pinot Grigio, assorted micro brews and the occasional crisp gin and tonic (with Rose's lime juice, of course ) as much as the next guy, but I play it very conservative with respect to duty.

If you're worrying about flying under the .02 limit, you're probably walking on the edge where you shouldn't be. Playing with fire (or firewater) and getting nabbed for whatever cockamamie reason but blowing a .015% and squeaking by is NOT a victory, it's an indication your judgment is in the wrong place.