This youtube video demonstrates the versatility of military Micro Air Vehicles (MAVs), otherwise known as bugbots.
Remotely controlled, insect-size UAVs are the ultimate in close or convert reconnaissance. Computer technology and battery power has finally reached the point where microbots — the next step before nanobots — are feasible. Given modern, mass-produced nanoscale computer chip technology, it is likely that the "brain" of each microbot will cost only a few dollars per chip. Quite unusual for defense technologies. (of course, the brain is only one part of a larger technology system, once you include all the remote control systems)
DARPA has sought technology like this for a while (BBC report from 2006). Maybe they are now a reality?