I made the standard shooterbot, the second example robot in the NXT 2.0 kit, and then modified it to be remote controlled. Two motors are used to drive the bot, with the third operating the front mounted shooter. Three sensors are attached; ultrasonic mounted on the front left, color on the upper right, and the Playstation 2 controller interface on the back. The example program has the bot protect a 40 cm circle, giving both a verbal and visual warning before shooting. The first version has a few problems; it advances to give a warning but doesn’t return to the original location, and the gun is inconsistent; it sometimes jams, sometimes shoots twice. I haven’t added any remote control support yet.