http://www.extremetech.com/extreme/107217-real-life-constructicon-quadcopter-robots-being-developed?print Click to view
http://www.frac-centre.fr/public/actualit/ftat01fr.htm Click to view
Thoughts:
I do like the physical simplicity and modularity. If a placement unit is damaged or destroyed, it can be retrieved and another one can take its place immediately. I'd like to see some ability to grip securely onto a building surface, though, in order to wield force-feedback tools like automatic spanners and nailguns, or to allow more precise placement of heavy items. The advantage is that the number of unit resources assigned to a particular part placement can be altered on the fly as conditions change: stronger winds would result in more copters and surface grippers being used per part. This would slow down the rate of construction, but not stop it entirely until conditions became too harsh for the placement units to continue.
And of course, with infrared lasers bathing the worksite, the assembly copters could work 24/7.