Are my strides different while walking versus running? Do you adjust your pedometer setting for your stride when going for a run? I used to be an avid walker so I know that:

Distance from my house to the track = .75 miles
6 laps that I run/walk = 1.5 miles
Distance going from the track back to my house = .75 miles

When added up that should be 3 miles no? Keeping my pedometer on the whole time it reads only 2.58 miles after I've done all that. Keep in mind that I am alternating between walking and running. How do I adjust my pedometer for this?

I've only had one pedometer, and didn't find it very useful, so am not really the expert, sorry. If it goes by stride length only, though, I'm guessing you can't make it read correctly if you're walking and running. Might want to switch to some kind of GPS type unit, if it's that important to you. If I knew the distance already, though, I wouldn't worry about it, and there's always google maps, or mapmyrun.