Thad Starner is one of the patron saints of the wearable computing movement. He uses a display that mounts onto his glasses and a Twiddler to operate a box running Linux. Check out the videos to see what he looks like from the outside, and what he’s seeing.
While I would personally prefer a solution slightly less intrusive (there’s got to be a better display available, and Mr. Starner carries a messenger bag full of batteries for his computer), I would love to see this sort of thing take off. I don’t see why a display embedded into my glasses couldn’t connect wirelessly to my smartphone, which is in turn connected to a Bluetooth Twiddler.
From the outside, it’s a guy playing with a small device. From the inside, it’s everything I need.