If you think you walk a lot at work, then what ever else you do, DO NOT buy yourself a pedometer, FFS.
My wife bought me one to ease my mind on my "feeling of need to get more exercise" during the day. Her theory was that I already walk way more than I think I do. She was right; I thought I walked about five or six miles per day at work. My pedometer indicates that I actually walked fourteen miles today while I was at work.
I knew it was a rough day, but I am not really sure that I need to know just how rough of a day it was.