The Ava 500, which iRobot will unveil at the InfoComm technology conference in Florida, is a so-called telepresence robot that has a 21.5-inch screen for a "head" — a bit like Skype on a rolling pedestal.

The telepresence robot (T-bot) project allows the reader to enter a mobile robotic device based on a radio-controlled model car equipped with a microminiature video camera and soundsystem.

In a telephone conversation, each person has a microphone and a speaker in the telephone handset, with each microphone linked to the other person's speaker. The analogous setup for visual telepresence is for each person to wear a see-through Head-Mounted Display which is linked to a telepresence robot at the location of the other person. In such a conversation, you would see the other person's face superimposed onto the robot face which was physically there before you. You could thus have a "face-to-face" conversation with a distant person, making eye contact and observing one another's facial expressions.