The "wearable computer" crowd typically lashes together wierd looking stuff that seems to have come from a bad sci fi movie--elaborate belt packs with wires hanging off them, strange goggles with built in displays--nothing you or I would ever get near.
What's the biggest "wearable computer" in the world? It's the iPod, which was designed with attention to both form and function, rather than as a technology demonstration.
Take a look at these new "computers" that show off technology that has been under development for some time, so this is not imaginary stuff--costs and marketing have not been worked out yet, but these kinds of gadgets are coming.