There's an increasing number of these about... moving, rolling, 'swarming'... the age of active, mobile, networking, and probably soon 'intelligent', surveillance devices is arriving... http://www.newscientist.com/article.ns?id=dn6932 http://www.rotundus.se/ David. Dr David Wood Global Urban Research Unit (GURU) School of Architecture Planning and Landscape University of Newcastle upon Tyne NE1 7RU UK tel: +44 (0)191 222 7801 fax: +44 (0)191 222 6008 e-mail: [log in to unmask] GURU website: http://www.ncl.ac.uk/guru/ Personal website: http://www.staff.ncl.ac.uk/d.f.j.wood/