What is an Accelerometer pedometer? - Accelerometer  pedometers uses electrical sensors to detect movement and acceleration - no moving parts. Depending on the type of model/accelerometer they can record movement back and forth, up and down and left and right.
Accelerometer waist pedometers are more accurate then pendulum pedometers as correct positioning is not so critical and accelerometers with a 2D Axis accelerometer (such as the G-Sensor 2026) can be tilted upto 30 degrees on the waistband, making it ideal for people with bigger tummies. They also have a non-step filtration to eliminate crossing legs or sneezing to be counted as steps!
 

For the 'Waistband Pedometer Category' is - the G-Sensor 2026 - it's a very affordable, extremely accurate 2D Accelerometer waistband pedometer with steps, KM, calorie and clock functions. It has a strong spring loaded waistclip , large LCD screen and very easy to use.