Just took a bus up Caledonia Road on the way home. I had been peering at some suspicious looking bits of the Yahoo imagery, which looked like streets but weren't traced at all. Sure enough, they are right there in this quite central location, and easily visible from the 91 bus route, and not on the map yet! So that's a reminder to me, that eliminating all the unnamed streets is not the be all and end all. There's still important refinements to make closer to the centre of London.