In 2012 Bikes Alive, fed up with the lack of protections for cyclists and pedestrians who are being killed on the street too often started blocking key dangerous intersections, starting with Kings Cross on January 9, 2012. In November 2013, over 1000 cyclists participated in a die-in vigil outside Transport for London's headquarters in Southwark following the deaths of six cyclists killed in a two-week period.
In 2005, members of the London bicycling community started a project to track cycling fatalities and other serious crashes. Reports on crashes and maps showing where they occurred can be found at the website - however this site hasn't been updated in a while.
From Joe Whil comes this recent film-short via Filmaka, "Ghosts," which is "a short documentary-style drama inspired by the Ghost Bikes memorials of London." To see this, click here.