The ascent of smartphone

Smartphones are evolving rapidly in sophistication. What will they be capable of in a year or two or even five years' time? How do you define a smartphone? Devices like Apple's iPhone, RIM's Blackberry and, say, a Nokia E61, are clearly the physical manifestation. But what identifies them as smarter than ordinary mobile phones? Is it just down to functionality? Smartphones now carry email client, Web browser, GPS functionality, desktop synchronisation tools, as well as organiser-type functions such as diary, contacts, notepad and voice recorder.