“Smartphones are mobile devices which utilize cellular and wireless software to enhance the user experience of mobile-enabled services by connecting to those services by direct ties into the operating system and hardware of the mobile device.”

“Smartphones are mobile devices which utilize cellular and wireless software to enhance the user experience of mobile-enabled services by connecting to those services by direct ties into the operating system and hardware of the mobile device.”

I'll blow all of your minds and say that I think that a smartphone is a smart phone. Bear with me.
A pretty phone can be one that has a pretty exterior or a pretty UI. Or both. This can also be a smart phone, but not necessarily.
An easy phone is one that has great UX (hence easy for everyone to approach and use). The Holy Grail is to have a phone that is smart, pretty and easy at the same time. This has not yet been accomplished.

So what makes a phone smart? What makes a person smart? It's the same impossible to define, yet everyone has their own personal definition sort of thing.

On the technical side, I'd still argue that a smart phone should take native apps and allow them full control (capabilities) of the hardware. And the UI, if needed. It should also be able to multitask till the RAM is drained.

But really, let me get back to smart, pretty and easy. Let's do the girlfriend analogy. There's smart, there's pretty, and there's easy. Ideally, there should be one person encompassing all these. But usually only in movies. So you stick with whoever seems like requiring the least number of compromises in your book.

Me, I would never give up on smart. In phones, at least

“Has the ability to be extended by software by the user or a third party to fit a users need”

Hence the differentiation from “feature phones” which can only have software installed at the manufacturers discretion

As for the E71 – I had the opposite experience to you But that just goes to show how variable the term smart is!

I've been tending to refer to things an having an open mobile platform, though smartphone, as a word, is still more widely understood, if poorly defined.

Here is what Wikipedia says:

A smartphone is a mobile phone offering advanced capabilities, often with PC-like functionality. There is no industry standard definition of a smartphone.[1][2] For some, a smartphone is a phone that runs complete operating system software providing a standardized interface and platform for application developers.[3] For others, a smartphone is simply a phone with advanced features like e-mail, Internet and e-book reader capabilities, and/or a built-in full keyboard or external USB keyboard and VGA connector. In other words, it is a miniature computer that has phone capability.