A few more newbie questions

1. Does anyone know how the "Calibration" function works? I pressed it inadvertently the other day and it didn't seem to do anything. Am I supposed to drive for a bit to calibrate? The manual does the explain this at all.

2. I've got a Sprint Treo 650 and had a few questions regarding Bluetooth functionality:

a. Has anyone gotten the battery meter and/or caller ID (for phone numbers not in your phone book) to work?

b. How does call waiting work? Do you press the left phone button on the steering wheel? And then how do you go back to the original call?