A personal audio player has a housing, an audio output device in the housing and an audio player in the housing and coupled with the output device for storing and playing audio files. A method for operating a base station in a mobile communication system includes generating a neighbor cell list including at least one cell, including at least one cell among the at least one cell in a first list disallowing a handover, and disallowing a handover to the at least one cell included in the first list. The center of mass of the damper 46 lies in a plane bisecting the angle subtended by the friction surfaces 48a and 48b. As such, a drop-in replacement and improvement on a mechanical critical vertical drift tool is provided herein. In more particular embodiments, the end user is authenticated in the enterprise network after being authenticated in the service provider network. Custom bit rate profiles for advertisements may also be defined, with the profiles being defined at a high granularity or a low granularity.