The history of London's Valley; Silicon Roundabout
GigaOM has a nice timeline of the events that led to the creation of the name Silicon Roundabout.
23 July 2008: I’m chatting in the office with (probably) Russell Davies, Ben Terrett and Matt Jones. We’re talking about the neighborhoods our friends work in in other cities, and I jokingly suggest that Old Street has become Silicon Roundabout. It feels very British, slightly awkward and a bit silly. I put it on Twitter.