SI Unit Stimulus

I had an interesting thought about a month ago, as I taught about SI Units to my Fall term Math 20 class: since the Federal government is wanting to employ people during this recession, why not take some steps towards switching to SI Units?

Merely changing all speed limit signs to kilometers per hour would provide many temporary jobs, and nearly all cars on the road show their speed measured that way.

I'm not sure what other switches would not cause too big a ripple of bother in industry, but there must be some similarly easy first steps towards SI Unit use. Switching to SI Units will eventually happen anyway; we might as well use that work as recession stimulus.