The USPTO just awarded Google with a patent on an "integrated finger-tracking input sensor device" for Google glasses which pretty much means that there'll be a trackpad on the side frame of the glasses. That trackpad probably means that the Project Glass system will be controlled with your fingers and not just your voice or eyesight.
The patent spells out use cases such as tapping, scrolling, etc. with the trackpad but obviously doesn't specify how exactly it'd work in tandem with other Google Glasses controls. Though having a trackpad on your glasses seems potentially useful, it kinda dumbs down the dream of these specs being completely hands free. Either way, Google is smartly stacking up patents for any type of sci-fi glasses to come. [USPTO via Engadget]