At the Apple Worldwide Developer Conference 2008 in San Francisco, as was widely expected, Steve Jobs has launched the iPhone 3G with the boast that it's "twice as fast, half the price".

The new model gets GPS, a new design, a lower price tag, will be available in 70 countries and the 16GB version will be offered in a traditional iPod white.

Stating that the first iPhone had an "amazing" introduction with "tremendous" critical acclaim, Jobs claimed that the device enjoys an "off the charts" 90% customer satisfaction rating with 98% of users browsing online, 94% using email, 90% are using text messaging, and 80% using 10 or more features of the phone.

Jobs revealed the company has sold six million iPhones until they "ran out" several weeks ago.

Jobs stated that the "next challenges" for Apple with the iPhone were 3G network support, proper enterprise support, third party application support, availability in more countries and making the device more affordable.

The Apple CEO said that 56% of people that want an iPhone but didn't get one say it was due to price.

The 3G iPhone is thinner, with a black plastic back, solid metal buttons, the same "gorgeous" display, camera, flush headphone jack, and "dramatically improved" audio.

Changing his tune from when the speeds were said to be more than acceptable, Jobs said that EDGE, the current way the iPhone connects to the Internet over cellular networks is slow.

Showing how 3G is almost three times faster at downloading content - before criticising other phone makers for slow browsers on their handsets - Jobs demoed an email attachment that took 5 seconds to download on 3G and 18 seconds on EDGE.

With the claim that "3G has great battery life on iPhone", promised times are 300 hours of standby, 2G talk-time now has 10 hours (as opposed to 5), 5 hours of 3G talk-time, 5 to 6 hours of high-speed browsing, 7 hours of video and 24 hours of audio.

As was heavily rumoured, the iPhone 3G also boasts full GPS support rather than just cell tower triangulation however it’s not clear whether the phone will sport 3D mapping.

Jobs revealed that the iPhone 3G will be rolled out to 70 countries in total - a far cry from the five that the original iPhone was officially available in - and will cost £100 for the 8GB-er when available from the 11 July (across 22 countries; Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Hong Kong, Ireland, Italy, Japan, Mexico, Netherlands, New Zealand, Norway, Portugal, Spain, Sweden, Switzerland, UK and the US) promising a "maximum" price around the world for the 8GB version of $199.

The price for the 16GB model will be $299 - with a white version of this size available too.

However the company failed to add a second camera for video calling, failed to add A2DP support for music fans looking to stream music to a pair of wireless headphones. Additionally the handset still doesn’t get Flash support nor does it get a video recording function from the same 2 megapixel camera as before.

Additional reporting by Stuart Miles.