One of Apple's biggest selling points for the iPhone is the user interface.

As most of you will know, the front of the phone has only a single button that returns you to the main 'home' screen with a single click. Everything else is controlled through the touch screen.

The interface looks gorgeous and works very well, except of course that it suffers from the same problem that affects all touch screens: human skin. The iPhone comes with a cleaning cloth in the box, and trust me you're going to need it.

Aside from having to wipe the screen every few minutes, the interface is generally quite intuitive. Most things work pretty much the way I would expect them to, which is a great relief given that the phone doesn't really come with a manual.

In general, it's pretty easy to navigate menus and options with one hand. The screen's resolution is terrific and the buttons are big and well laid out.

Because the entire operating system and all the applications were built by Apple, everything works in pretty much the same way.

There are a few tricks you will learn over the first few days, such as when the device is locked you can still access the basic iPod controls by double tapping the home button, meaning that you don't have to unlock the phone and navigate to the iPod program just to change tracks.

It also took me a while to figure out that, when looking at email, you don't have to go into the email to delete it.

If you slide your finger from right to left across the title (rather than left to right) it offers the option to delete it. It's great for getting rid of spam.

There are a heap of similar tricks and tips that you'll either figure out for yourself, or find on Apple's forum or a range of other discussion sites.

Inside the iPhone are two fancy things called an 'accelerometer' and a 'proximity sensor'. These basically allow the phone to know how it is oriented and how close it is to something.

The proximity sensor allows the phone to know when you put it to your head to answer a call, at which point it shuts off the screen. This is a handy feature as it means you don't accidentally hang up on someone, or make a conference call to China with your cheek.

The accelerometer puts the phone in landscape mode when using certain applications, such as the iPod, Safari or Photo viewer, simply by tilting the phone on its side.

It's a rather nifty feature, although what did irritate me was the lack of this feature in the email and SMS applications as I found the landscape version of the keyboard a lot easier to use, but I'll get to that tomorrow.

In short, it's obvious that Apple's designers spent a lot of time trying to make the interface as simple as it is pretty, and there are a number of quite useful features and functions as long as you don't mind doing it Apple's way.

For the average consumer this may not be a problem, but as a geek I like to fiddle and customise my devices, and the iPhone is having none of that.

There is no way to remove or change the layout or order of the icons, even if you're pretty sure you're never going to use the 'Stocks' application.

The upside here is that the user interface can always be altered through software updates, so hopefully Apple will listen carefully to its users and implement changes that the majority of owners call for.

Tomorrow I'll be looking at the applications that the iPhone provides and how well they work.