While watching KerbalKon, it was suggested in jest that a mod should be created to keep track of how far you've slammed your EVA across the surface. Honestly, I couldn't find a reason not to do it. This plugin adds a module to your EVA's that allows you to enable PuntJeb's statistics. When enabled, a window will be displayed that provides:
Velocity
Last punt achieved
Longest punt achieved
Total distance traveled since going on EVA.
PuntJeb will also inform you of your last distance traveled should your Kerbal be... less than fortunate. Velocity and Total Distance will also work when in an external command seat (rovers included) and is an excellent way of seeing how much ground you've covered.
Simply right-click your kerbal and select the option to toggle PuntJeb.
Directions are simple, just open the zip and copy the PuntJeb folder into your game directory's "GameData" folder.