Cool! Since the beginning of 2012, the cities most represented among my readership are (in order of most visitors to fewest):
London
New York
Toronto
Chicago
Los Angeles
Sydney
Melbourne
Seattle
Houston
Washington
San Francisco
Dublin
Austin
Dallas
Brisbane
Philadelphia
Denver
Boston
Vancouver
Surprised to discover I have more readers in Brisbane than in Philly or Boston!
UPDATE: Should have said that this is not an exhaustive list, just the top cities.