He is the author of the exemplar and influential blog How to Save the World which covers topics as diverse as environmental philosophy and activism, natural enterprise, narrative and storytelling, social networking and personal content management and innovation. He has written a number of articles on collaboration (scroll down to the 'collaboration' heading), and recently collaborated with Mitch Ditkoff and Tim Moore of Idea Champions and Carolyn Allen of Innovation Solution Center on a survey to discover what the charictaristics of an ideal collaborator might be. Some of the results of this survey have been incorporated into the collaboration page (as well as material from his blog).
The first and standard Meta Collab question: how do you define collaboration? This is can be a very tricky question of course, so even a cursory description will do fine ;-).
In your work with Wikipedia and Wikicities, which activities in your opinion and experience are the most collaborative? The least?