This DIY robot turret comes as a easy to setup kit or you can build it yourself. The multi-role robot comes with a webcam for watching your back, a fan for keeping cool, and a pellet gun with laser sight plus color tracking for some harmless target practice.
The kit is built around two HS-322HD Hitec Servos. The kit has a USB interface and you can control it from the PC. Joystick controls give the dual axis robot some extra flexibility. If you know your code, you can even program the open source firmware and take it ahead from there.