From AH.com comes an a link to web applet that allows you chart the relative popularity of last names. Publicprofiler/Worldnames has the census data for only for most of Western Europe, North America, Argentina, India, Japan and ANZAC. So it has some limitations but it is still gives some interesting answers. The statistical model seem to fall apart when it deals with subregions smaller than 100k it returns weird numbers. In the AH.com thread many people were discussing the frequency of their "real" names not their user names.
- "Mulroney", as a last name not as swear word, is more common in Quebec than in Ireland as a whole.
- "Ruggles", are densest in the NWT. However the numbers might be deceptive since at a frequency of 275 per million only about a dozen in the NWT must be named Ruggles for that rate.
- "Campbell" is densest in PEI with 1% of the island with that surname.