Expectations are running high that Steve Jobs will announce a 3G iPhone at Apple's developer conference on 9 June.

Analysts are already predicting that the phone will give a big boost to mobile applications.

The higher data speeds of 3G connections, coupled with the Wi-Fi capability, are likely to bolster certain mobile applications that are poorly used in the US.

"The iPhone could become the mobile video delivery device of choice for many consumers by providing a compelling mobile TV and video proposition before mobile broadcasting networks, such as DVB-H, become widely available," said Mark Heath, an analyst at Analysys Mason.

However, Heath pointed out that Apple's market share is limited by its practice of selling the phone via one telco per country, and warned that this strategy had to change if the company wants mass market take up.

Apple's share of the US smartphone market has fallen steadily over the past quarter from 26.7 per cent to 19.2 per cent, according to figures from analyst house IDC.

By contrast Research in Motion's BlackBerry is more popular than ever, and now accounts for nearly half of the total market, up from barely a third at the end of 2007.