There are at least two companies producing robotic systems that can lay bricks and they are both pretty cool. Fastbrickrobotics is an austrailian based company and their robot mason is helping to fill the gap between the housing boom and the shortage of masons. The Wall Street Journal reports that a mason in Sydney can now command a six figure salary.
Construction Robotics SAM, which is short for Semi Automatic Mason is a much smaller unit and meant to work along side a mason.
Have a look at the web sites for some cool videos of these robots in action.