Driving home from The Serpent Mound a few weeks ago, we passed through Belfast, Ohio. We have also been to London, Ohio, and, of course, OCLC is located in Dublin, Ohio. I was in Cardiff, Wales, a little while ago [ppt], and will be in Edinburgh, Scotland at the beginning of July, but, although I must confess that I have not looked very hard, I am not aware of a Cardiff or Edinburgh in Ohio. Three out of the five capitals is not bad ;-)
I travelled to Springfield, Illinois, from O'Hare recently. There was a flight to Springfield, Missouri, leaving from the same gate a short time apart. We were double checked to make sure we were heading off for the right Springfield (you would have thought that it would be simpler to have such flights leaving from different gates.)
Last year, I spoke at an ASERL meeting in Atlanta. I was showing Open WorldCat and looked for libraries in Georgia holding The Star Wars cookbook: Wookie cookies and other galactic recipes. The first three libraries were in Athens, Marietta and Columbus, all in Georgia. I did a double-take, because, of course, Athens, Marietta and Columbus are also cities in Ohio.
It seems to me that libraries have not tended to control place-names as much as their colleagues in museums and archives? With the growth of interest in mapping applications, there are a variety of nice uses for such data one could imagine, especially where it is geo-referenced. For example, in conversation about FictionFinder after my presentation at CIL 2006 [ppt], Emily Lynema suggested an application which provided references to novels written about places on a driving itinerary. It may not have been the most serious suggestion, but it is indicative of possibilities.