Found while browsing the internet: This is handy way to instantly blank your screen like we could in the old days with dos utilities, and it already exists within Win 7 if you set it up.
" There's a really easy and simple way to do this: Create a new shortcut on your desktop. Browse to scrnsave.scr in C:\Windows\System32, click OK, click Next, name the shortcut as you wish, click OK. Now you have a shortcut to run Blank Screen screensaver on your desktop. Double click it to instantly blank the screen, move mouse or press a key to return to desktop. Screen stays blanked as long as nothing happens, and it does not disable your normal screen saver. You can use the same method to launch any screensaver (.scr) file. by Kari"
note: you have to go pretty far into the C:\windows\system32 folder to find the file.