Question : Problem: How do I turn off iMac screen when mirrored to a Samsung Plasma

I have a 22 inch imac leopard 10.5. I attached my Samsung Plasma to it using mini DVI to DVI converter and then a DVI to HDMI cable and then finally to my SAMSUNG plasma HDMI input. Thats confusing. But thats not important really. In short my imac is attached to my samsung plasma. Now my question is. I want my imac to be displayed on my samsung plasma but I need the imac screen on sleep mode or just black or inactive. So I just need my SAMSUNG PLASMA on but the imac screen blank. cause right now both of them are on when I mirror it. and it bothers me when im watching movies on my plasma through my imac and both of them are on (showing the movie) and they are side by side. So when I watch movies I see two monitors, the imac and the samsung. SO is there a way of mirroring the imac to plasma without both of them on. i want the imac on blank screen and my plasma mirror the imac. Thanks

Answer : Problem: How do I turn off iMac screen when mirrored to a Samsung Plasma

O crap that is right you did say Imac Doh!
This is said to work though I can't test it as i have only lappies and towers.
http://forums.macrumors.com/showthread.php?t=456172 In this thread i found this quote:
As of 0.4.5 you can blank any display that you are not using XBMC on.

So, yes, you can blank the iMac screen while still watching the secondary display. And vice versa should you so desire.
http://xbmc.org/

Another good possibility is switch rez x. Again i can't test it. You will have to put the haxie engine ape on your machine.
http://www.madrau.com/html/SRX/New.html
Even if SwitchRez X doesn't have a direct path to what you want you could always make a display set that you know the iMac can't handle which should blank the built-in display while keeping output to your external. Be careful with this tool and always keep the test first and resume box ticked as this is a powerful tool.