Here's something I was referred to by Pharyngula. It's an interesting historical snapshot: a site that uses phonebook and census information to build maps of surname frequencies. Just type in your last name, select a year, and click, it shows you where people with your name were living in 1850, 1880, 1920, and 1990.
This all made possible, gratis, by Hamrick Software, the home of VueScan, an excellent tool if you use a scanner or digital camera. VueScan supports more than 400 scanners and 140 digital camera raw files and you can download a trial version for free here.