How many different screen layouts do you use? One? Two? Walter Biscardi has a selection to choose from depending on what he is doing.
Great food for thought from Walter on customising the FCP layout. He has a different layout depending on what he is concentrating on: colour correction, audio or just rough cutting. Head over to his blog to see all of his layouts, but just as a taste we include his rough cut layout.
It would certainly make you concentrate on the external monitor and not get that 'follow the cursor' problem when playing.