I have mixed feelings about this. Of course when we walk, we don't pause each second and ponder all of the map around us, we just walk and avoid stuff in our current area (and maybe not even do that very well) as humans. However, robots really don't recognize objects in their environment very well right now. Most just bounce a sonar ping now and then and really don't know what they're looking at. I think robots have a long way to go for true autonomous navigation and being able to ignore things. It will take some sort of anticipation system of knowing what's coming up rather than a real time ping see whats there and avoid it method. Until robots know their map, or at least can anticipate whats coming up, they've not really progressed much beyond a first stage bump into walls and retreat type robot. So really, very few robots have mastered autonomous navigation where they could ignore data to navigate successfully.

Maybe mobile robots could do like Hansel and Gretel did by scattering bread crumbs along the path. This didn't work very well as you may recall, because birds ate the crumbs, so it would be essential to keep birds from entering the house.

Another method might be to equip the robots with odor sensors that has been developed for sniffing out drugs and stuff. Paths could be laid by dragging smelly things around the house for the robots to follow.

I remember a story about a blind man in Boston that had such a good sense of smell that he could recognize people by their smell. The only time this failed was when he walked by the Fulton fish market one time, tipped his hat and said, "Good morning ladies."