Non-Intrusive Wearable Gesture Recognition

I've been playing around with the idea of recognizing gestures (ideally even a chorded-keyboard-style input mechanism) using a non-intrusive wearable.

The use case I'm imagining is for input into devices like Google Glass or smartwatches - I can read messages but if I want to send one, I can't type on it and speech recognition is very public. I can get my phone out, but that breaks my flow. What if I had a device that I could wear all day (and not disrupt my day-to-day activity) and would allow me to interact with these devices?

For something more concrete, a couple of my previous (very experimental) hacks in this area are documented at https://docs.google.com/presentation/d/13EwSIBdhaovuAe3RJfpzi4YYiC4hGBt38MMDM8cdc9E/edit and https://docs.google.com/presentation/d/1VxnOetfblT5vhFM-UeB944pJW1i8twwZkoSruqbFB_o/edit.

I don't have a concrete plan for the technology to use for this - it's still very much in the research phase, but I'd be keen to meet anyone interested in investigating this.

By day, I'm a software developer (and am happy with pretty much any programming language), but I've done a bit of hardware stuff in the past.