In March, the ISS had to be maneuvered to avoid space junk:
NASA said Monday the space station had to dodge part of an old satellite. Sunday night's firing of on-board thrusters pushed the orbiting lab up a half-mile.
Then I remembered that arstechnica did a great piece on how the ISS is moved and in that article:
Additionally, the station has several sets of thrusters that allow it to rotate and translate. The Zvezda service module is equipped with thrusters, and there are thrusters on docked vehicles like the Progress resupply craft and the ESA ATV that can also be employed. Space shuttles could also be used when they were still operational. For a typical debris avoidance maneuver, the station will be subjected to delta V of between 0.5 and 1 meter per second.
I am wondering what is the power required to move the ISS? I am not a physics expert but in space as there is no friction, I don't think it would need massive amounts of propulsion to move the ISS.
A more curious question is could a human "push" the ISS and make it move?