The best types of Pedometers for running are 3D Pedometers. They can be worn practically anywhere and measure acceleration in all directions. Which means they will provide you the most accurate measurements.
Pedometers that track steps, miles, pace and activity time are usually ideal for runners as they provide a bunch of different data points from which they can try and improve with each outing.
The SC2 Pedometer will provide you all of this data and has been proven effective by avid runners and newbies alike.
