If you don't already own one, chances are you want to! The iPhone has been the breakthrough device of the past couple of years. Indeed there hasn't been an electronic gadget with such an amazing market penetration since the launch of the iPod back in 2001. Apple has once again found the winning formula - the iPhone is cool, it's useful, and it's here to stay.

It's easy to see why the iPhone has been so successful. Unlike other mobile phones, the iPhone's actual telephone function is nothing special. But the internet-enabled iPhone is more than just a mobile phone. It is the best example of 'convergence' in the handheld device market yet seen. Its fun, friendly and easy to personalise with items such as phone covers.

iPhone Apps are the Difference

As anyone with an Apple iPhone knows, the unit is all about apps " small applications that can be loaded on the phone easily by visiting the Apple iTunes App Store online. From your iPhone or from your desktop, users can trawl through various categories and select all manner of applications.

In July 2009, there were over 65,000 third-party applications officially available for the iPhone and iPod Touch on the App Store. While some apps cost money (most paid-for apps are priced from US$1.50 - $3.00) many more are free, offering a huge array of options.

What are iPhone Apps?

So what do these apps actually do? With the app of your choice, you can do everything from finding the nearest public toilet (ShowTheLoo) to racing around the track (Fastlane).

You can make internet calls with the Skype app, or check the latest weather, traffic, or public transport conditions. You can find the nearest bar (and read a review), read Moby Dick on a reading app such as Stanza, play Tetris, Space Invaders or Tap Tap Revenge (the most popular iPhone game yet!).

You can watch YouTube videos, buy gear on eBay, find your nearest wifi hotspot or record voice memos. Check stocks. Listen to radio half a world away, keep a shopping list (I use ShopShop), mark off your to-do list, download and read docs or PDFs, identify a song playing in the supermarket with Shazaam, look up a cocktail recipe and then tweet your friends about how good it tastes with one of the many Twitter clients, such as TwitterFon, Tweetie, Twinkle, Tweetsville and more!

Phew. And that's just the start.
But why are iPhone apps good?

The runaway success of the iPhone (and the iPhone apps) is easy to understand. Here's why it's the world's most desirable device:

iPhone convenience

Having an internet-connected mobile phone with a large, bright screen and a ton of apps allowing you to organise your professional and social life has been a dream since brick-like mobile phones first hit the market in the 1980s. And now, with the Apple iPhone, it's here.

Device convergence

It's not just a mobile phone. It's a PDA (and has pretty much ruined the Palm PDA and its rivals). Its an iPod. It's a portable gaming device. It's an internet-enabled computer. It's a TV. It's a micro home cinema. It's a radio (internet streaming). And all in one simple, sleek 11.5cm long, 135g handset.

Lifestyle convergence

The proliferation of apps for the iPhone means that social network and network gaming fans " previously tethered to their desktop machines " have been liberated. On the iPhone, users can access Twitter, Facebook, YouTube, eBay and many other popular social networking, sharing and transaction sites.

The internet capabilities mean that with an iPhone, you have the internet in your pocket…perfect for settling a friendly argument about who sang “Everywhere I Go� in the early 80s (QED), who won the 1974 Australian Rules Grand Final (Richmond), and what year Geoffrey Rush won the Best Actor Oscar (1996).

iPhone style

The iPhone continues Apple's flair for elegant, desirable design with the sleek iPhone. While Apple was synonymous with clean white products, the black iPhone is a work of true design beauty.

iTunes micropayments

Paying for apps in the iTunes app store (from your desktop, or from your iPhone itself) is the simplest payment mechanism yet devised online. Set up your account and you can buy apps by simply entering your iTunes password. Cracking micropayments has been a significant breakthrough, and has had a huge impact on app sales.

SDK - open access

For programmers, Apple released an SDK (software development kit) in March 2008. Since then, the availability of third party apps has skyrocketed.
iPhone developments

Since the launch of the first iPhone model in the US in June 2007, there have been a couple of major developments. One year after the launch, Apple released the iPhone 3G which featured faster 3G data transfer speeds and assisted GPS functionality. And 12 months after that, in mid-2009, Apple released the iPhone 3G S (s stands for speed), with even faster internet speeds and memory capacity boosted to a maximum of 32gb.

Apple has gained much from this annual drip-feed of updated devices and enhancements; we can proba