Not sure if this is considered data or voice (data would be free to umlimited plan users) or what the latency might be which is the key to successful Push to Talk Applications. Nextel for example is less than a second once the initial connection is established. You need to at roughy one second of the delay makes usage much too annoying…
Orange has announced the commercial availability of Talk Now, Europe’s first advanced Push-To-Talk over GSM service. The first device able to take advantage of the new service is the palmOne Treo 600. [PalmInfocenter.com]