Some areas are location specific. Richmond VA seems to be a .NET and Java town mostly. My team's stack is Apache httpd PHP and Java mostly on Linux. A little scripting in Python and bash.
It would be cool to have a map showing what stack/language is most marketable in what area, so that one can adjust time spent on learning new tools depending on where they want to go. But maybe these things evolve faster than the time scale involved in getting enough experience to be attractive for employers.