By Darren Waters
Technology editor, BBC News website
The greatest success of Apple's iPhone lies in the realisation that most phones you have owned previously are compromises.
The iPhone is not perfect - far from it - but it genuinely re-moulds the expectations we have for mobile devices.
And it provokes a reaction among gadget lovers and ordinary members of the public that no other phone can match.
I have been testing it for the last two weeks and whenever people see it they want to hold it, touch it and play with it. And they are genuinely amazed by some of its features.
KEY iPHONE RIVALS
Sony Ericsson W960
T-Mobile Sidekick Slide
Under the strict letter of the non-disclosure agreement I had to sign with Apple to be loaned the phone I was not supposed to let anyone hold the device.
Nor was I to demonstrate it, display it, let anyone photograph it nor even "discuss" it with anyone outside my "immediate family".
Ridiculous? Absolutely. But perhaps a reflection of the iPhone lunacy that has gripped many people - including, evidently staff at Apple itself.
In the US it is known as the JesusPhone - because of the hysteria and hype that surrounds the device.
But let's start with the disappointments - it is a 2G device and not 3G. Anyone expecting to use the phone to surf websites or access content over the mobile network will be in for a shock.
Graphics and picture-heavy websites take an age to load. But RSS feeds and mobile-friendly websites (such as news.bbc.co.uk/mobile) load quite quickly over the 2G Edge network that O2 offers.
I also found it sufficiently speedy to send and receive e-mails on the go. Sadly, O2's Edge network only covers 30% of the country so if you are not in a major urban area, you will experience painfully slow data connections.
The phone has built-in wi-fi and you can access more than 7,000 of The Cloud's hotspots for free. Web pages load very quickly over a wi-fi network and there is none of the usual "hang", or delay, that is associated with mobile net devices.
As a work productivity device the iPhone cannot match Blackberry
The web browser successfully redefines the mobile web experience and over a wi-fi connection it is - for the first time on a phone - a pleasure to read sites on the go.
The iPhone overcomes the physical limitations of screen size by letting the user zoom into sections of a page with a double tap. The whole page can then be dragged around with a finger.
For a phone which boasts of being an internet communicator it lacks features such as instant messaging (IM) and voice over IP.
Apple might have had trouble finding network partners if the device had come with the Mac's IM and talk client iChat, for example. But the firm could have taken a lead in this field and revolutionised on-the-go communications in the way Blackberry did for e-mail.
The phone also lacks the ability to sync data - such as calendar details and contacts - wirelessly, either through short-range Bluetooth or over the mobile network.
The iPhone is also Apple's premier iPod
The camera that comes with the phone is also deeply disappointing. It offers a measly two megapixels and while the sensor in the phone is decent, images are often poor quality unless shot in direct sunlight.
However, the success of the phone lies in its marriage of touch screen and user interface.
Many mobiles have touch technology but they are generally poorly implemented or a painful hybrid between touch screen and keypad.
The various functions of the phone have been knitted together brilliantly - it is child's play to text or e-mail from a contact's details, or to add calendar events and then open web pages from a link in an appointment. These are the simplest of things but by stripping out cluttered menu options Apple has taken out the fear from technology.
The programs and features are well laid out and there is none of the usual "hunt the settings" scenario that accompanies most phones.
Its underlying operating system - based on Mac OS X - is very robust. I have lost count of the times my personal handsets have crashed or frozen and required the battery being removed and restarted. Of course, you can't actually remove the battery from an iPhone.
Programs on the Apple device slip easily in and out of running and I cannot report a single "hang" or crash.
Other handsets boast touch features - like the HTC Touch
It is also very easy to overlook the iPod aspect of the phone. It is a fully functional music and video player and syncs with iTunes.
The touch screen user interface which lets the user flick between album cover art, or artists, genres and playlists will soon be copied by many other handset manufacturers as the sincerest form of flattery.
Sadly, the iPhone only comes with 8GB of flash memory - and no more can be added through memory cards.
In years to come the device will undoubtedly have more capacity, but if you want access to your whole album collection on the go, the iPhone probably isn't the convergence device you have been waiting for.
The iPhone isn't for everyone - it is not a true Smartphone device, the storage capacity is fixed and limiting for people with large music collections, the camera is low quality, it lacks true internet communication capabilities and the 2G handset is slow for data connections over the cell network.
But in many ways it succeeds in the way the original iPod did.
Both are flawed devices. But like the iPod, the iPhone will force every other competitor in the market to raise its game.
And for that consumers should be thankful for the iPhone - even if they have no intention of buying one.