For the last two years or so, we have been working on studying social media in the context of London. By combining what Twitter users in a variety of London neighborhoods talk about with census data, we showed that certain topics are correlated (positively and negatively) with neighborhood deprivation. Users in more deprived neighborhoods tweet about wedding parties, matters expressed in Spanish/Portuguese, and celebrity gossips. By contrast, those in less deprived neighborhoods tweet about vacations, professional use of social media, environmental issues, sports, and health issues. More recently, we launched two crowdsourcing websites. First, we launched urbanopticon.org, which extracts Londoners’ mental images of the city. By testing which places are remarkable and unmistakable and which places represent faceless sprawl, we are able to draw the recognizability map of London [1,2]. The site has attracted tens of thousands of players, and I will show you the results published in WWW last year. The second site is called urbangems.org. This crowdsources visual perceptions of quiet, beauty and happiness across the city using Google Street View pictures. The aim is to identify the visual cues that are generally associated with concepts difficult to define such beauty, happiness, quietness, or even deprivation [3,4]. The site has been awarded the A.T. Kearney Prize and has been featured in falling-walls.com 2012 in Berlin.