Turning mobiles into walkie-talkies

New "push-to-talk" services that turn mobile phones into walkie-talkies with unlimited range could soon make text messaging obsolete.

The services let users choose a recipient from an instant messenger-style "buddy list" on their phone screen, press a key and start talking.

The message, which can be up to 30 seconds long, comes out through the recipient's mobile's loudspeaker almost instantaneously.

Push-to-talk has proved immensely popular in the United States, and Nextel, the mobile phone operator which dominates the US push-to-talk market, has 12 million customers for its service.

More > BBC Online