RE: How fast is it really?
Stablock,
I agree your idee might be an easy way, but you need someone to help you.
Have you seen the small ones that actually connect to inline skates as well?
And as with the GPS you don't need to run next to the Savage to read the speedo, haha, they also save the max speed, average speed, time etc. and you can reset it and check it AFTER the run.
Chris