PiPanther Robot is the ideal Christmas present for big kids. The tank is powered by a Raspberry Pi and is build for modding.
Out of the box PiPanther is equipped with WIFI, HD camera and is controlled by a smartphone app. But an API means anyone can create their own turret additions. Twan Springeling is asking for a modest €5,000 to develop the prototype but will send you one for €160 if you back it on KickStarter.