This mod allows you to smoothly change your character's movement speed to levels between walking and running. It is done by holding the LeftShift key and scrolling with the MouseWheel to change your movement speed. When the LeftShift is not being held the MouseWheel will zoom the camera as usual. The original functionality of LeftShift is removed. CapsLock can still be used to instantly switch between running/walking.
This mod is useful because NPC's have more levels of movement speed than the player has in vanilla. Using this mod you don't have to switch between running/walking all the time to keep up with them.
The file and more details can be found http://www.skyrim.nexusmods.com/mods/29743.