Electronics, Lighting, & Gadgets - Put Cheap Wireless Computer on Wrist?

I've been avoiding buying a cycling computer mainly because I don't like to have a lot of stuff on my bicycle. I know that's silly, but I like the clean lines of an uncluttered bike.

I like the idea of a wireless computer that goes on your wrist, like a watch, but those seem to start at $200.

Has anyone tried putting an under $30 wireless computer on a wristband? Think it would work?

Also, do the GPS units calculate speed from the global positioning, or do they require a spoke-mounted magnet and sensor?

I dont see why it wouldn't work, but why? There are small computers that are unobtrusive. Also, the distraction of looking at your wrist to know your speed, etc. might compromise your safety. And you might "lose" data briefly if you stretch (i.e. if the unit goes out of range, which is usually only a few feet).

But that being said, it probably would work.

I believe the GPS-based computers use the GPS system and therefore do not need any sensors.

Also, do the GPS units calculate speed from the global positioning, or do they require a spoke-mounted magnet and sensor?
They do everything via global positioning.

The Garmin Forerunner 305 can calculate speed either by GPS or by using a magnet on the wheel. I don't know about the other GPS devices for biking.

The instructions for my Sigma wireless indicate a limited area to mount the computer in relation to the transmitter. Should be within a 30-degree cone above the transsmitter and less than 90 cm. distant. Of course other units may differ.

Thanks for the info. I ordered a Cateye Micro wireless, and I'm going to install it on the handlebars. I shouldn't take this minimalist stuff too far.