This might be what you were referring to a few years back:

http://www.rcheliweb.co.uk/
(click on the logo to enter the site. Then click on "upgrades" on the left side of the next page to get to the speedo tach page)

Has anyone done this? I'm thinking of doing the same thing with a bike speedo I already have on hand. The guys in Europe use the KPH setting instead of MPH. I just wonder how it can translate the spinning of a small gear instead of a large bicycle tire and still be accurate? If anyone here in the states has done it, let me know how it works.

Jesse