I recieved my free walk-o-metre the other day and i was sure i did more steps than it registered. So today I proved myself right! I clipped the free one onto my right hip, and my bought one onto my left - low and behold - my right leg has done 2069 steps and my left leg has done 4429.
Either it the free one doesn't work right, or i have been hopping most of the day without my knowlege.