" car's accelerometer and brake light "

Fletch, I think what you are trying to say is that the Dead Reckoning features utilizes the vehicle speed sensor signal generated from the vehicle speed sensors and reverse light signal to let the PNAV know which direction it is traveling in.

SiRF is not the only company working with DR, there has been a few companies that contacted us regarding this new DR capability for portable nav systems and cell phones, and it seems this DR feature will mostly be use for pedestrian mode where the nav unit can take you from the parking lot to the office or shopping center and possibly navigate you inside a shopping center or sport complex.

Am I to understand that mechanical connections are not needed & this is a totally self contained unit??