I've come across two of them whist cruising around the London, one at the top of Kingsway / Southampton Row in Holborn and another in Stoke Newington, near my old (ware)house. both are prime areas for t*sser taxi drivers or bendy buses to mow you down :evil:
I've more appreciation for them now I know what they are though, just thought it was bloody art students trying to be 'conceptual' again....