Wired had an article on added a magnetic sense to your touch. It's interesting to see another way to add senses that isn't technologically prohibitive. However, getting surgery done, however small, for it is a little insane. I can't imagine a knife to my finger tips. That's gotta hurt.
It reminds me of the article in BBC that I read about using the tongue as an interface conduit for spatial information. They fed sonar information to a tongue actuator so that people can find their way through a maze with sonar information. It's actually kinda neat, though it's still in its preliminary phases.
I wonder if remote-sensing and remote-controlling augmentations of humans would combine as tools for specialized human workers.
I'm sure the military is interested in something like this, though I can imagine it being a fad or fashion.