This AddOn will calculate the distance the player's character has traveled, how many "steps" they have taken in that distance, and the amount of "calories" that would have been burned had the player actually run/walked that distance in the real world.

This WoW AddOn is also available through Curse Gaming. You can see the project page at http://wow.curse.com/downloads/wow-addons/details/wowpedometer.aspx. :)