One one of the many things that have the potential to do both great service & also great harm to the human race is robotics.
We've already taken a huge ethical leap towards the negative with the creation of military robots. I've lamented the apparent future Robot Army that is on a subtle, yet unstoppable, path that should concern all protoplasmic beings.
The Colbert Report featured "Bumbot," created by a US Defense worker-turned-bar owner to keep derelicts off the street after dark. It is equipped with lights, loudspeaker, & water cannon to disperse local homeless and vagabonds.
It's almost humorous... as long I'm not the shady character this heartless enforcer is soaking on a chilly night. At least it can't be equipped w/ a taser & flame-thrower, like it's creator would prefer! I think it's just a little too soon for robots with lethal force to be patrolling our streets. Once we see how successful they are in Iraq, though, I'm sure neighborhoods everywhere will be looking forward to weapon-wielding machines guarding our every move...