Cell Phone Questions

Have you ever had questions about how your cell phone works?

I thought this article from TidBITS was interesting that explains:

1. How your cell phone calls follow you.
2. How cell phones work in cars and planes (including the real reason that airlines don't want you to use your cell phone on a plane).
3. Why text messages work when your phone won't ring.
4. Why you sometimes receive voice mail when your phone didn't even ring.
5. Why the iPhone GPS is faster than the GPS in your car.