In article email@example.com, firstname.lastname@example.org wrote:
I have an 20" iMac (intel) and a secondary dell 24" dell monitor. I would like to power off iMac monitor while I'm watching a movie on the external monitor. Quicktime allows to use background color on this display, but I want to completely power off the monitor Anyone knows how?
Simple. Connect external DVD player to Dell monitor, select DVD input on Dell, and Command Option Eject the iMac to sleep the display.
I have a similar iMac plus Dell 24 inch setup to you (iMac G5 rather than iMac Intel). I never could figure out a way to do what you ask for. But since I also use the Dell as my TV (from a VCR) and DVD display, I am getting used to flicking through multiple screens working at once.