US and World Surnames

In the National Geographic, an interactive map of the relative uses of surnames in the US.  This is a fun style infographic, but difficult to get specifics from.  Related, you can also search for the relative occurrence of surnames worldwide by using this WorldNames service.  Which claims to provide data down to a county level.  Though I found some of the results illogical.  Note that it asks for an email address, but you do not have to enter a valid email.