True to form, Apple has gone totally OTT in hyping the iPhone, but there’s no denying it’s an intriguing piece of kit.

Right from the off you get the feeling the iPhone is something special - unlocking the device requires you to simply slide a bar across the display with your finger.

Just five physical buttons grace the 11.6mm thick chassis: a power button, speaker mute switch, two buttons to control ringer volume and the Home button, which returns you to the main menu from any window.

Touch-screen displays always look good, but rarely do they actually enhance usability. However, Apple has bucked this trend with the iPhone. It took us less than an hour to feel at home with the device; it even excels when using the small Qwerty keyboard to bash out text messages.

The predictive text software helps speed things up - for example it will expand the touch-sensitive region of a letter if it’s the most likely next key-press. Strangely the keypad only works in portrait mode; the keys could be far bigger if it could switch to landscape as when entering a web address.

Both websites and photos look great on the 3.5in display, and zooming in and out by sliding two fingers on the screen is impressive. Video also looks great, although viewing angles aren’t so hot so you’ll need to look at it straight on.

Other applications include Google Maps (there’s no GPS receiver, but it’s good for planning how to get from A to B), a calendar and the ability to view office documents attached to emails.

It’s not all good news though, and one of the biggest disappointments with the iPhone the lack of 3G support. It will hook up to O2’s Edge network (around 100Kbits/sec), but coverage is sparse at present. Those in non-Edge areas will have to make do with GPRS (sub-50Kbits/sec).

Considering Apple wants users download music and surf the web, the lack of 3G is surprising to say the least. Apple says it’s a battery life issue, but we’ve seen plenty of 3G phones that can last over four days and, if you want to boost battery life, 3G can usually be switched off.

Thanks to built-in Wifi you can speed things up by logging onto your home or office network. It will also link up with any of the 7,500 hotspots in the UK provided by The Cloud.

Another design issue the recessed headphone socket, meaning it’s very unlikely your own headphones will fit without a third-party adapter. Apple will argue it wants people to use its headphones as they house the microphone required for hands-free calls, but to us it’s an infuriating feature. And while audio quality during MP3 playback is fine, we were disappointed during phone calls with conversations sounding muffled.

Battery life is quoted at eight hours talktime, seven-hours video playback and 24-hours audio - with pretty heavy mixed usage we needed to charge it every night. As with iPods the battery isn’t removable so you can’t, for instance, take a spare with you on holiday. And if it starts playing up you may have to pay to get a new one fitted professionally.

Look solely at its software and the iPhone sparkles; it’s in a league of its own compare it to other similar handsets. But consider the device as a whole and cracks soon appear in the iPhone’s shiny armour. The lack of 3G is bizarre while other unexpected flaws limit its appeal - such as the inability to record video with the 2-megapixel camera (which also has no flash), no FM radio, lack of Bluetooth A2DP and MMS messaging support. It’s also expensive - £269 is what you’d expect to shell out for a Sim-free phone.

You’re also tied into an 18-month contract with O2, starting at £35 per month with 200 minutes and 200 SMS texts, which is very stingy compared to other tariffs. Free use of The Cloud’s Wifi hotspots and unlimited data usage help sweeten the deal, but when you’re stuck using Edge or GPRS you’re not going to want to be downloading huge files.

The lack of 3G and various other omissions won’t bother everyone, and regardless of its high price the iPhone is guaranteed to fly off the shelves. Indeed, as a first-generation product it’s very impressive - we’d just recommend holding off until iPhone 2 arrives, whenever that may be.