You could have a mouse down listener, and as long as you don't get a mouse up, change the location of the TitleWindow based on the current position of the mouse.
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Greg Lafrance - Flex 2 and 3 ACE certified
Flex / AIR Development, Training, and Support Services
Nice tip, I'll try.. !!
Panel has this logic. Take a look at Panel.titleBar_mouseDownHandler and Panel.startDragging. You might be able to reuse or call some of this code.