(Telecompaper) Telefonica has unveiled a service called Social TV at Mobile World Congress, which the company describes as a "pioneering and unique" initiative in the world of television. The service, which is still in beta, will allow users to interact with other people directly on their TV screen without having to connect via other social networks such as Facebook or Twitter. Telefonica said viewers will be able to use Social TV to comment, debate or talk to friends or contacts during any live programme via a conference call and simultaneous chat system.