Whilst I was visiting the GSM World show in Cannes earlier this year I stumbled upon the folks from FastMobile and had a live demo of their push to talk application FastChat. It basically uses GPRS to turn your mobile phone into a walkie talkie, with one to one or one to group features.

I was dead impressed that it worked as advertised on the stand, and now they’ve launched it officially. Anybody in the UK can sign up from the Website because it uses the company’s own servers (it doesn’t matter which service operator you’re using as long as you’re signed up to GPRS.)

It costs �6.99 a month and currently works on any of three new Symbian smartphones – the Sony-Ericsson P800, or the Nokia 7650 or 3650. More phones are scheduled soon.

It’s the nearest I’ve seen to a killer GPRS app, and I think that it could well become a huge money spinner for the market as a whole. I mean how many times have you wanted to call someone and just ask quickly ‘where are you, are you here yet?’ while waiting at a meeting point? Now consider being able to do it instantly without incurring anything more than a teeny tiny GPRS data charge. Now you’re getting the idea.