i have a Powerbook and like to use the dual monitor feature when i'm watchin movies or doing anything with graphics.
is it ok to plug and unplug my monitor anytime, or do i have to turn off the computer and switch it?
Duff-Man says....yup, just plug and unplug whenever you like - no need to restart. If stuff doesn't show where you want when you hotswap just open the monitors prefpane and click "detect displays" and all will be well again....oh yeah!
it will set you up to span if you plug in the dongle, with or without monitor. Actually, this is probably just for the 12" as the larger models have full DVI.
don't forget you can drag your menu bar over to your other monitor in the preference panel. This will allow you to use the large monitor as your primary display. OS X will keep this preference and move your dock and menus back to your monitor every time you reconnect. It really is easy and works flawlessly.