http://i.imgur.com/o7Pvn.jpg
Thanks to Rogerius Josephus Boscovich for first posting this over on the Phora. I was amazed at the results.
1) The dominance of Islamic surnames in areas like Tower Hamlets really should ram home the reality to some: London is being lost to the English.
2) The amount of people named Smith!! :eek::D
Anyway, here's the link: http://names.mappinglondon.co.uk/