Friends, I am planning to buy a fone. Budget upto 15,000. I have thought about buying a w700i or n 3250 or k750i. I have other fones in mind, too. But problem is that i don't understand what is Symbian. (1)watz the diff. btwn s40,s60 and other symbian levels? (2) what is the use of symbian? (3) DOES HAVING SYMBIAN MEAN THAT VIRUS CANNOT ATTACK THE FONE?? PLZ HELP!!!!