if I dial *#92702689# on my nokia 3330 cell phone, it tells me several things, including serial number, manufactured date, purchase date, times repaired, transfer user data, and hours the phone has been on.

I was wondering how this type of thing works...and how it would be possible to discover other numbers like this (sure you can look them up, but where is the fun in that?). I really dont know too much about cell phones, so I am looking into them now.