French company Apeera has developed technology that turns the mobile phone network into a potentially vast peer-to-peer network.

The technology gives users a digital store cupboard for their own media files and lets them pass them on to anyone who wants to use, listen or look at them on their own handset.

Apeera's creators said it could prove popular with phone companies keen to convince customers to start using new multimedia services.

Big success

Ever since the appearance of Napster, peer-to-peer networks have been hugely popular with internet users.

Logos and icons are going to become pictures, ringtones are going to become music files

Adrian Bisaz, Apeera spokesman

These networks let people browse and search the shareable files on the hard drives of any other member of the same system.

Now Apeera has found a way to do something similar for mobile phones.

Its peer-to-peer system gives users their own storage area into which they can upload images, music files and games for use on their handset or to pass on to anyone else.

"Peer-to-peer is the cornerstone of making a service successful," said Adrian Bisaz, Apeera spokesman.

Mr Bisaz said mobile phone operators got most money from customers calling each other or sending text messages and passing on ring tones than they did from other services.

As phones start to handle more sophisticated types of data files, being able to swap and share them easily would be key, he said.

"Logos and icons are going to become pictures, ringtones are going to become music files," said Mr Bisaz.

Locked out

Currently many operators are trying to persuade customers to swap their handset for one that can handle multimedia files such as images and polyphonic ringtones.

Phones are getting more sophisticated

Some phones use software known as Java that lets them do much more sophisticated things.

Sites such as Midlet.org are springing up that let people download new Java games into their handsets.

However, most handsets have a small on-board memory limiting the number of messages, images, sounds or games they can store.

Apeera, said Mr Bisaz, gave a phone an effectively unlimited memory.

The Apeera system can be used by any phone that can use Wap - a set of specifications that converts webpages into a format that a handset can understand and display.

Apeera users can send files to any Wap or Java phone, even those that are not signed up to the service.

Mr Bisaz said many operators were interested in Apeera because it allowed customers to get more out of their handset and gave the operator a regular point of contact with subscribers.

They also liked it, he said, because pre-paid customers can also use it. Key groups of users, such as teenagers, are effectively barred from using many multimedia services because operators have not worked out how to let them pay for them.