A new social media application for mobile phones launches from London on Friday. Trutap, a downloadable app, offers blog posting, multi-protocol IM, group SMS, web photo-sharing and access to existing social networks and, to monetise all that, is building mobile ad infrastructure. VentureBeat likens Trutap, which is aimed at 18- to 24-year-olds, to Australia’s Bluepulse and a rash of other startups: “It focuses instead on parts of the world where broadband penetration is relatively low, and where a mobile phone is a teenager