So you bought a car phone, and you still don't get enough work done during drive time. Cheer up. A Wheat Ridge, Colo., start-up called Zirco Corp. has come out with PowerTrip, a device that turns your car's cigarette lighter into an A/C receptacle for computers, fax machines, and other electrical appliances. And is it safe to have people running spreadsheets at 70 miles per hour? Not to worry, says Zirco. "We anticipate and expect that the audience we're selling to has the intelligence to decide what's safe and what's not," says sales vice-president Neil Zimmerman. Let's hope he's right.