Just so you guys know, and i am sure that the laws vary in other states, but you can get a dui even if you blow below the legal limit. It is up to the discretion of the officer to decide whether or not you are too intoxicated to drive. Unfortunately, once he has made that decision, it is up to you to prove that you were not. I know people that can drink a six pack and still be completely coherent, but at the same time, i know people that cant talk after one beer. The breathalyzer/BAC only helps the officer get the conviction. It doesnt make the decision of whether or not to arrest you.
That is how people get dui's for marijuana, prescription drugs, etc. Obviously you do not blow a .08 if you are on drugs but you can still get a dui. If you are driving erratically or appear to be putting yourself or others in danger, even if you have only had one drink, you can still get a dui.
If you are going to drink, dont drive.