Google glass sample video
There's several techniques you can use to emulate Google Glass' eyesight videos. The next best thing would probably be to buy a pair of camera (sun-)glasses. Judging by what you're trying to achieve, your best option is to buy any camera from pivothead, they all film full-HD 30fps video. Other options include the SunnyCam Glasses and the iVUE Camera Glasses. There's also the Zeal HD Goggles, but those are probably impractical in temperate environments.

Alternatives include the GoPro Hero 3 (Head-mounted camera, as you suggested), the ContourROAM2 (Waterproof) and the Braun SixZero (or any other head/helmet-mounted camera). If you're on a tight budget you might want to manufacture some sort of head-mounted camera yourself.