The only time I was in London (I think it was in the spring of 06), we didn't bring any camera, and the mobile phone I had at that time didn't have a camera either, so we bought a disposable one that took some really ... horrible pictures! I had to throw them away because in most of them you could hardly tell that was London :). Anyway, I kept a couple of them, like this one where you can see the London Eye... kind of.