For years, it bothered me that my character was always running while everyone else was walking. Sure, you can reduce the amount of force you apply to your left thumb stick (if using a controller), but that just didn't feel "immersive" to me. I used a neat little config to esp editor made by Wolfmark, called Skyrim Speeds available at http://www.nexusmods.com/skyrim/mods/1603/? to save some time.

Using his tool you can create your own custom *.esp. I searched Nexus, albeit swiftly, and was unable to find a file that would do what i was trying to do. Feel free to edit, change, share.

Player and NPCs Walk                100 (+24.84%)
Player and NPCs Run                  125 (-66.22%)
Player and NPCs Sprint               450 (-10%)
Player and NPCs Sneak Walk       47.2 (Default Value)
Player and NPCs Sneak Run         222 (Default Value)
Bow Drawn Walk                        120 (Default Value)
Bow Drawn Run                          135 (Default Value)
Horses Walk                               165 (+22.22%)
Horses Run                                 450 (Default Value)
Horses Sprint                              600 (Default Value)
Horses Swim                               210 (Default Value)
Werewolves Walk                       150 (114.29%)
Werewolves Run                         450 (+13%)
Werewolves Sprint                      600 (+13%)

End result is basically a Walk and Sprint mode for player and NPC. Player will no longer run like an Olympian, only walk, and run at some normal approximation of human speed. This has an effect on your stamina whenever you run, like in real life.