‘This is not like a normal council event...it's so much more', words from an attendee to the recent launch of Comoodle by Kirklees Council; their response to a growing appreciation of the merits of the sharing economy, and the use of radical innovation to address complex social challenges.

Comoodle is an online platform that facilitates the sharing of ‘stuff, skills and space' by citizens and for the community, and forms part of the winning cohort of projects involved in Bloomberg Philanthropies' Mayors Challenge - an ideas competition designed to encourage and support European cities to generate big, innovative ideas that tackle acute social problems, and have the potential to spread to other cities around the world.

Cities including Barcelona, Warsaw, Stockholm, Kirklees, and Athens are implementing very different ideas, from addressing political disengagement to ageing populations, but they are coming together as a group to share their experiences. Through face to face events and a virtual community, Innovation Unit are supporting this process by facilitating the cities to share their stories, reflect and learn from one another's experiences, and, crucially, build on the potential for those ideas to spread to other cities.