United States

All 50 states now have two statutory offenses[1]. The first is the traditional offense, variously called driving under the influence of alcohol (DUI), driving while intoxicated/impaired (DWI) or operating while intoxicated/impaired (OWI). The second and more recent is the so-called illegal per se offense of driving with a blood-alcohol concentration (BAC) of 0.08% (previously 0.10%) or higher. The first offense requires proof of intoxication, although evidence of BAC is admissible as rebuttably presumptive evidence of that intoxication; the second requires only proof of BAC at the time of being in physical control of a motor vehicle. An accused may be convicted of both offenses, but may only be punished for one.

Source: http://en.wikipedia.org/wiki/Driving_under_the_influence