What are pedometers?

Some articles on pedometer, pedometers:

... A pedometer is a device, usually portable and electronic or electromechanical, that counts each step a person takes by detecting the motion of the person's hips ... of length (such as in kilometres or miles) is desired, though there are now pedometers that use electronics and software to automatically determine how ... originally by sports and physical fitness enthusiasts, pedometers are now becoming popular as an everyday exercise measurer and motivator ...