How to turn off the monitor

I have my MacBook
Hardware Overview:

Model Name: MacBook
Model Identifier: MacBook2,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.16 GHz

operating a home theater system. I do not require the monitor to be on while operating the home theater.

Question: How do I turn off the monitor without putting the MacBook to sleep?
Please keep in mind I still need a picture on the big screen, so I need to turn the monitor off but have video output still on.

Try running your MacBook in "Clamshell" mode:

Apple Portables: How to use your computer in closed clamshell (display closed) mode with an external display

HTH,

- Nick

Or just turn the brightness all the way down.