Ever notice how retail clerks always seem to be on their coffee break when you have a request? Not the proprietor of a compact-disc outlet that opened last week in Minneapolis. The clerk behind the counter boasts an encyclopedic knowledge of the 5,400-item inventory, and never leaves the store. The attendant can't, because it is a robot -- the first to run its own shop.

Invented by Robert Cahlander and David Carroll of the Robot Aided Manufacturing Center in Red Wing, Minn., the robot has a 400-lb. arm that dispenses discs, makes change and processes credit-card purchases. Its computer brain also tracks inventory and cues up tunes for customers who punch their requests on a keyboard. The designers may franchise an army of the devices. Behind every great robot, of course, there is a human -- in this case a worker who drops by once a week to replenish the stock and collect the receipts. And maybe, says Carroll, "clean the glass with a little Windex." Even a robot, after all, has pride.