NORFOLK -- If you're annoyed by motorists who chat on cell phones then get ready to be more frustrated: A new survey ranks Virginia sixth in the nation for drivers who send text messages behind the wheel.

The online survey of 4,820 people was commissioned by Vlingo, a Cambridge, Mass., company that markets voice-recognition software it says can be used as a substitute for texting.

The survey released Wednesday found more than a third of Virginia drivers acknowledged typing the electronic messages on their tiny cell phone key pads while also trying to navigate traffic.

Nationally, 28 percent of those surveyed confessed to "driving while texting."

The survey found the worst offenders in South Carolina, where 40 percent say they text and drive. The least offensive were in Arizona.