Compared to other Wi-Fi enabled devices, the iPhone has a distinct advantage in that it knows when you’re in a Wi-Fi hotspot and will automatically connect to it (provided you’ve passed the security measures) by default. However, when you step out of Wi-Fi range, you’ll drop back to using your mobile network to transmit data.

The original iPhone was only capable of EDGE speeds (or slightly faster than dial-up speeds) and in Australia, only Telstra offers an EDGE-capable at the moment. Anyone else using an iPhone on any network would have been stuck with a slower GPRS connection.

The iPhone 3G has since put an end to that issue. The iPhone 3G incorporates a tri-band HSPA chipset that will work on most Australian 3G networks. It offers incredibly fast data speeds, theoretically capable of 7.2 Mbps download speeds although will be slower than that in reality.

The iPhone also allows you to make and receive phone calls and browse the net (at EDGE or GPRS speeds) even when you’re outside the 3G network. Although the quick speeds of browsing will be gone, you’re unlikely to ever be able to go back to the slow speeds of a GPRS connection.

Of course, it’s important to remember that the cost of mobile data in Australia is considerably expensive. Contrary to popular belief, the introduction of the iPhone has not been a catalyst for cheaper data plans from the Australian Telcos. Out of Telstra, Vodafone, Optus and Virgin who have released the iPhone in Australia, Optus have the most consumer-friendly pricing, although they still don’t use the true potential for internet browsing over 3G on the iPhone.