from the beginning of the smartphone era we are commenting on things like "why do we need a smartphone?, the sole purpuse of having a phone is make a call-talk-disconnect!.." practically this is what phones are meant for, but the mobile technology has matured so that it has combined 3 different world.
we use to carry gadgets like a phone to be connected, a music player to be entertained on the move and a PDA r a laptop to cater the out of office business needs, now all these has fused in to a single device called SmartPhones.
There is a clear distinctive look btw a smartphone and a pda-phone. smartphone Nokia-symbian mostly fall under pearl DFRD(device family reffernce design) according to which u need a keypad and a screen for the user interface . And more over a keypad is a better option for a smartphone than a keyboard, coz its a phone which has the functionality of a PDA but firstly it’s a “phone”[talk-listen thing]. And smartphone is a phone which can make u smart(not intelligent) ;) PIM+telephony = smartPhone