You're not going to carry a mobile phone, GPS, digital camera, media player, stand-alone PDA and other gadgets, but we want to carry the functionality of at least some of these devices everywhere we go. It's better to carry one small gadget that does all that. So everything is going into the phone. And we like it that way.

Handset makers also face what I call the "Microsoft Word Problem." For years, Microsoft justified feature bloat in Microsoft Word by saying that everybody wants only 10 per cent of the existing features in Word, but that everyone wants a different 10 per cent. That's why Word needs 100 per cent of its current feature set.

It's a good point, and one that's applicable to mobile phones. One user might say, "all I want is a phone to make calls and take great pictures that I can easily upload to Flickr." Another might say, "all I want is a phone to make calls and give me turn-by-turn directions." The next thing you know, companies are selling phones with extensive camera functionality, sophisticated GPS, advanced media playing ability, fast downloads, big screen, full QWERTY keyboard, social networking applications built-in, Wi-Fi, international network support and the like. How "simple" is it going to be?

First PDAs, then cameras, then music players, and now GPS is being baked right into even moderately priced mobile phones. Gartner analyst Thilo Koslowski predicts that within four years some half a billion mobile phones will have GPS functionality (far outpacing stand-alone GPS devices). GPS functionality also topped the list in an In-Stat of mobile phone features people would be willing to pay for -- more than half said they'd pay extra for it.

These are incredibly high numbers given that hardly any mobile phones had GPS just two years ago. This transformation will increasingly be driven by consumer demand - the same people who say their phones are too complicated.

So who's going to deliver the first super easy-to-use super phone?

What users are clamoring for is a phone with a beautiful screen and a brain-dead simple user interface like the iPhone, with the core business functionality and keyboard performance of a BlackBerry, with the high-quality camera of some of the LG phones. We want GPS, 3G and great media management.

As a BlackBerry user I hate to say it, but I think Apple has the best shot at delivering the first truly powerful-but-usable phone. If you list the most common complaints people have with each of the major phones, at least two items on Apple's list - lack of 3G and lack of GPS - are likely to be addressed as early as this US summer. It will be easier for Apple to add these missing features (in fact it's inevitable that they will be added), than it will be for Microsoft or Palm or RIM or Symbian or any of the other mobile phone software makers to get anywhere near the iPhone's simple UI.

If the next-gen iPhone also gets a nice performance boost, better business applications and an optional wireless physical QWERTY keyboard, Apple will probably go very far in attracting millions more users who are clamoring for both power and simplicity.

In the longer term, we can't rule out Google's Android. Nor can we completely write off any of the other vendors that may find the simplicity religion as Apple runs away with their customers.

Negroponte is right. Simplicity really is the biggest challenge that handset makers face. And Apple's already got it. Now all it needs is more functionality. And that's easy.

Mike Elgan writes about technology and global tech culture. Contact Mike at mike.elgan@elgan.com or his blog, The Raw Feed.