The 'locative' research that Intel is doing is also relevant to this discussion (my apologies if this URL was already posted to the list): Urban Atmospheres http://www.urban-atmospheres.net/ A research agenda specifically focused on exploring the facets and issues of computing in public urban spaces. Jabberwocky http://www.urban-atmospheres.net/Jabberwocky/ A mobile phone application for visualizing and interacting with our urban landscape of familiar strangers. (initial trials are underway and a new version of the software will be release next month).