OK, I don’t know if this is going to break down any of your brick walls, but if you are like me, it was fun to play with.
I started on Public Profiler Worldnames and entered my maiden name Gillespie.
This is the distribution of the name across the world. Well at least in the countries they are tracking. Below the map, I discover there are more Gillespie’s per million in Ireland in any other country.
Clicking again on the dark blue area, I see:
Now I don’t think this helps me in my genealogy research all that much. This tells me where the names are most likely to come from, not where my ancestors come from. But I love maps. So what the heck — it was fun! :-)