One thing that I find annoying when using a gadget while riding a bike is the act of actually USING it... This includes taking your eyes off of the busy traffic around you to focus on the tiny display of a mounted speedometer...
Matt Richardson may have the solution with his Dynamic Headlight that projects your speed on the road in front of you.
-Check out the video demo below:
As of now his design is in a 'very' rough prototype phase (as you can see from the video). After he works out the bugs and refines the components, he hopes to reduce the size into a compact unit that simply attaches to the handlebars.
:: Jump to 2:00 to skip to see the Dynamic Headlight in action ::