Istanbul and Dubai are gateways to the modern Middle East, a market that is growing faster than (and is younger and bigger than) that of the United States.
Santiago, Chile, has made a name for itself as one of the most foreign-entrepreneur-friendly cities on the planet, and as a test bed for launching into Latin America.
Tallinn, Estonia, is one of the world's most internet-connected cities, with a deep pool of technical talent thanks to all the Skype alumni running around.
Shenzhen, China, aspires to be the Silicon Valley for hardware makers, a place where accelerators are eager to help you build, test, refine, and make a million of something all in the same day.
If these cities aren't already on your radar as lands of opportunity for your company, let this serve as notice that they should be.