At work, I have a multiple monitor setup, where my primary monitor is not a touchscreen. Since I work principally with touch events, I need my second monitor (the touchscreen) to be the one where my Flash stuff appears, but since it's not the primary monitor I run into the trouble of having to make it the 'primary' monitor whenever I need to test an application.
However, Adobe Air has some nifty multiple screen support. This code moves the native window over to the second monitor during runtime.
Keep in mind, this won't resize your window, just move it to the top left corner of the second screen. You'll have to do that separately.