Driving after drinking moderately; or, how do you know where .08 is?

[Godfather80]

I was in conversation with some friends and the subject of drunk driving came up. We all agreed that it is a terribly irresponsible thing to do (we used more explatives than this, but you get the idea).

The funny thing was that none of us exactly knew where the line between having "been drinking, but still fine to drive" and "legally drunk" was.

To the best of my knowledge, I think from high school health class, the average man processes about 1 drink per hour. So, my logic is that with more than 2 "unprocessed drinks" in you, that you shouldn't drive.

Am I anywhere near correct? Is there a better way of figuring this out?