I wanted to build a Full Wearable Human Interface. A pair of gloves acting as a mouse-keyboard, and a pair of augmented reality glasses will replace the usual interface devices. The user will have total freedom, allowing them to work even from lying in bed (Workers' Unions may be sharpening their knives). You can use it to play, too.
The idea is to prevent several gesture-related conditions common in people working on computers most of the time. Carpyan tunnel syndrome and other musculoskeletal syndromes could be reduced significantly, although that should be demonstrated from a clinical trial.
The most challenging part of building such an interface is the reliability of the finger-movement reading systems.
My approach was reading the flexural angle between the 2nd and 3rd falanges. The angle will tell the microcontroller which key are you pressing and will send wirelessly the imput to the computer.
My first tests went really well. However to develop the system I would need a full team of engineers of many kinds (electronic, textile, communications,...) or a 250 years lifespan.