I’ve actually been working on a project very much along these lines – principally as a way of learning ASP.NET MVC. The beta site has now gone live at http://www.jumblist.co.uk. Comments via the feedback link would be welcome.

It only covers a few groups in the east sussex area at the moment but I hope to expand it to cover more of the country and also to move it away from relying on freecycle/freegle for content.