The IDeA website has the good story of an innovative and collaborative partnership
Building learning partnerships and leadership capacity: Royal Borough of Kensington and Chelsea and Oxford City Council development year. In October 2007, the Royal Borough of Kensington and Chelsea and Oxford City Council teamed up to put a joint cohort of 15 middle managers through a development year. Kensington and Chelsea has successfully run development years, but this was the first time it would partner with another council.
More information: http://www.idea.gov.uk/idk/core/page.do?pageId=10643258
I wonder how many more collaborations there could be like this that are a) happening or b) could be happening...?