T-Mobile is hoping to appeal to the 16-24 crowd with a new instant messaging service on select handsets.

Launching on just six handsets to start with, the operator hopes to be able to offer the service on around 20 handsets before Christmas with the promise of new models coming online every week.

Coming pre-installed, or retro-installed via a free download, users will be able, for £3 a month, to send unlimited instant messages to each other as long as both are signed into the service, although this skyrockets to £4 a day when roaming.

The system, which is available from today, will offer connectivity for Windows Live, Yahoo messenger, AOL and ICQ although not allow Skype or Google Talk users to chatter.

The handsets available from today are the C902, W760i, W580i, and W350i from Sony Ericsson and the 5310 and 6500 classic from Nokia.