I found this use of the Myo (to control the robotic arm of an amputee) really cool -- it seems like they found a life-changing use for what might have ended up a cool toy -- http://developerblog.myo.com/meet-the-man-with-a-myo-control... -- not sure how perfectly it works though.
Probably not particularly well as the Myo band only detects a handful of super basic gestures, and unless they have changed their stance in the past year or two they refuse to expose the raw data to developers. This makes it impossible to distinguish more than their predefined gestures.
