With 3G subscriptions still nowhere near mass-market popularity, ITU Telecom World 2003 in Geneva offered an opportunity to identify the killer application. But it appears as elusive as ever.

Application vendors pushed mapping systems and video calling software, while industry application sellers touted services such as video clips and taking online information services like lastminute.com to mobiles.

But manufacturers and operators were more sceptical. With high levels of debt among most network operators, there is a desperate push to find some function that will increase average revenue per user and improve profitability.

"People are not as keen on video phone conversations as we had expected," admitted Keiji Tachikawa, president and chief executive of NTT DoCoMo, which boasts a million 3G subscribers.

"It only works if the callers are close, like lovers or grandparents and grandchildren.

"Videoconferencing, however, is used by business. We are focusing on this and entertainment as we believe these are the killer applications."

But others feel that the search for a killer app is missing the point.

While applications may drive growth in a particular environment, for example SMS use, which helped the explosion of mobile phone use among the young, the industry is still groping in the dark.

"There is no one application that will do it, but then again there isn't for PCs either," said Dr Irwin Jacobs, president of Qualcomm.

"The early part of the 3G base are business users who never go anywhere without a laptop, so the connectivity angle can't be ignored.

"The key surprise is that people will pay extra for the video clips, and from revenue that could be the killer application."

Orange rolls out its 3G service in the UK next autumn. "It isn't about building the killer application but the killer environment," Sol Trujillo, chief executive of Orange, told delegates at the conference.

"It's about encouraging and enabling usage, not force-feeding applications on handsets. Eighty per cent of users never use more than 10 per cent of the applications anyway."