You can use a pedometer. It will count your steps, calculate distance and give you the time.
I have a map wheel that I run round a paper map. (I'm doing a virtual walk), it's easier than trying to figure out where an invisible footpath goes using something like mapmyrun.
I also have a Garmin 405, it was a pressie but prolly has more features than I want. I think the Garmin site has a facility whereby they recommend the best watch for you based on what you want to do with it.
Garmin thingy
Edited: 05/09/2009 at 10:01