Don't you start a call with Hello..Who is this? every time you get a call from an unknown number? Why does technology depend only upon the contacts of the mobile phone? I wish there exist a Header-Variable like concept in cellular technology where in every mobile number will carry along with it, a certain set of data of the caller, like his name.
How do you think Google manages to redirect you to www.google.co.in when you actually type google.com? The browser is the client software that you use, and your server, google.com will get the details like IP address, Time zone, locality, Browser (Whether IE/Firefox). By manipulating these details, the server software makes certain decisions!
I am unaware of the technical intricacies that enables mobile phone communication. I wish it existed, or I knew about it, if it already exists, for it will help track-down so many things and better the life of the end user. My Aunt, who is not so well-versed with a mobile phone usage, asked me, "Why is it not showing your name Viki?" after I gave her a ring. "It displays my daughter's name though!", was her next best observation. Well, she wasn't actually aware of the fact that the only number in her mobile phone contacts was her daughter's!