New hope for cities might just be here, with the increasing realisation that we don't always have all the answers. How, would people use a new public space? Should a particular street be closed off? Perhaps the best way to find out is just to try things out on a trial basis.
The Globe and Mail has a good article on how some major cities, New York, Paris, Toronto, Calgary and Vancouver are using experimentation to transform themselves.
An idea is percolating in my head about this but I will have to get a few more people behind it before I will tell you what it is.