I have been an OpenStreetMap Foundation board member with a "platform" of contributing back to OSM by performing un-glamorous but necessary administrative tasks as membership secretary and StateOfTheMap conference organization. A wider motive for standing was to help broaden OSM from its UK starting point to a genuinely international organisation. We had made great progress in European and western countries and needed to keep going.
I then headed the OSMF License Working Group to shepherd through a highly contentious license change and am still chair now. My main motivation is that I want what I map now to be freely available and usable in 100 years time without legal snafus.
I also head the OSMF Management Team. This is an attempt to support the OSMF board with the more day to day things and evolve a process where we can cope with issues in a timely and responsible manner without ever forgetting that we support but do not control the OpenStreetMap project.