Regressively miniaturize prosthetic hands, and employ people via VR to control them
Just use existing drawings of prosthetic hands, to create smaller ones, which we could use to create even smaller ones, etc.
For example, build a laboratory, and employ people over the internet, from virtual reality worlds, by massively selling cybergloves (like we today sell computer mouse) with force feedback, and allow game players to practice by doing surgery to all kind of small animals like insects, worms, bugs, with the hope that we could scale this to a degree, where the nano-workforce is widely available to fix us dexterously and efficiently before we die.
At each scale of magnitude, we could have a progression of applications and business, because at each scale of magnitude of such hands, we would have different killer applications. For example, maybe 10x smaller hands may be able to fix gastrointestinal tracts and broken electronic, and help construct 100x smaller hands, which in turn, could help construct even smaller hands, etc. The crucial thing about this idea is the ability to scale and mass-produce such smaller hands with tactile feedback, as we would be trying to leverage on the abundance of natural humans who are naturally very adept at using hands (the ancient marvel of opposable appendage), and the progression in the VR technologies.
The imaginary product, would be a combo of stereoscopic camera and 2 robotic arms connectable to a computer, exposing the data stream and the API to another systems, such as virtual reality game, where it would become available to players wearing cyber-gloves. One can also imagine the product packaged into 3D-printer-like boxes, or attached to snake-like or spider-like bodies, enabling flexible attachment to target locations.