Is there any relation of mobile model no's with any h/w installed in it..................if not then y r they named like NOKIA 6600,N0KIA 2100,NOKIA 1100,ETC....
Model no. matters....!!!
may be " 3 and 5 were for younger population, 6 business class, 7 for experiments, 8 for top mini models and 9 for communicator. 2nd and 3rd number also were logically added, " --according to blayv in www. esato.com/board/
This thread will help for sure: 
Why doesn't Nokia name models starting with 4 ?
Why doesn't Nokia name models starting with 4 ?
Thanks Vishal, 4 the link... i missed the thread then
thank u all for the info.
Nice Info