““Segways are a classic example of this phenomenon. You've seen them on occasion in malls or in airports, looking something like an old-fashioned lawn mower gone vertical, ridden around by someone in a security professional's uniform. Kind of dorky looking, but don't kid yourself. The gyroscopic balance control is fabulous, and the control movements once mastered are graceful. The hope was these devices would become a universal transport mechanism. Why didn't that happen? In a word: stairs. Stairs are pesky little devils that crop up everywhere, and Segways do not handle them well at all. That's what we call a showstopper.””
