My neighbors have what's called an Invisible Fence. I'm not sure of the official name for it, but it works wirelessly with a collar so that the dog doesn't go beyond the invisible fence line.
It works to some degree, but my neighbor thought the dog was trained enough and went to change the battery from the collar and let him out. And he took off! Luckily he came down to my yard!
I have never seen the likes of this yet. From the explanation of how it works, I think that it looks something that's nice. I'm not sure if I need it now for my dog but I'm going to keep it in mind.
This is interesting and something I had only heard about today. I do like the concept though and what it is used for, so many dogs I have known get out of their garden and run out into the street and some end up hurt if they get into traffic so it's great they have something like this to be used to prevent dogs from going too far.