The UK’s first event devoted to the new set of social media tools such as Twitter will take place at the Southbank in London on May 20. In keeping with the subject matter, the Media140 event will be short and sweet, lasting just four hours, from 2pm. Packed into those four hours will be a host of top-grade speakers, including journalists and representatives of The Guardian, Reuters, the BBC, and of course The Times, whose very own Joanna Geary will be discussing the impact of social media on local news.