Cool tip discovered just now whilst watching a video podcast in iTunes.

The overlay controller that shows up when you mouse over a movie window, like this,

itunes movie window with overlay controller

can be moved by clicking in one of the non-control areas and dragging. Handy for when there’s info being obscured, but you’d like to keep the controls active, such as this,

itunes movie window with overlay controller moved

I’m probably the last in a long line of people who already knew this, but just in case. :)