Sharp has rolled out a trial Voip (voice over internet protocol) service for users of its Zaurus PDA.

It will enrol 1,000 Zaurus users in Japan for the service, which will allow them to talk with each other via wireless LAN networks for free until the end of March next year.

The service uses the Linux-based Zaurus SL-C700 and SL-B500 PDAs and the trial is being made available to PDA users that also subscribe to NTT's Hotspot wireless LAN service.

A microphone headset will be given away to anyone that registers for the trial and each user will be assigned a seven-digit telephone number starting with 550.

About 300 hotspots in the cities of Tokyo, Osaka and Sapporo are being used for the experiment.

After testing, Sharp plans to sell the service, allowing users to communicate with each other for a monthly fee of a few hundred yen (in other words a few pounds) a month.