No other new service in the last year rose so much rumors in the market as Truphone (http://www.truphone.com) did since its beta launch at VoN Autumn America, Boston, 2006. It was not just a new VoIP service like many others in these years, they brought something people spoke about in the past, but was mainly behind the scenes: VoIP over mobile network. And it is not voice channel replacement, but convergence between fixed and mobile networks, between SIP and other IM/VoIP protocols out there -- this is more than what VoIP did to fixed lines in the past, and could open a new era for mobile communication.
Googling will reveal lot of comments about Truphone target and its features, which makes no sense to repeat here. You can just make an account and test it by yourself.
I will underline only one idea presented there: what is behind the service. Basically the Truphone VoIP platform is pure open source. Database server, web server, sip server, media server, operating systems. Isn't it a bit mad to do it so? Well, seems not, the platform was built starting with March 2006 and in about 6 month was able to run in beta mode, while a lot of efforts were conducted to develop client side applications, web interfaces and many bits and pieces for transconding, handoff and interoperability.
Would a vendor (even the big ones) be capable to deliver a solution for a brand new business model in such time frame? James Body, Director Networks Truphone, spoke enthusiastically about the flexibility and power of open source: how one can combine and get best out of it for a solid business.
Download slides of Truphone - Reversing The Paradigm