There are a couple of programs that will toggle the screen completely off. I forget what programs do that, but I believe they are free and you can just place a shortcut on your today screen to toggle your screen.
Free screen toggle programs:
http://translate.google.com/translat...2Fpsshutxp.htm
Not free, but included in as an "extra"
SPB pocket plus has it
XCPUScalar has this option as well, but don't over/under clock in the interest of battery longevity