Tells OmniFocus to open and activates the Quick Entry if it is not already open. Does nothing if it is open. This script is modified to work with the Standard App Store version of OF2. It assumes that your Quick Entry shortcut is “control + option + command + t” like mine is. Fork and modify at will!

OopsieFocus.applescript

set GTDAppName to "OmniFocus"
global GTDAppName
set GTDAppToUse to FindRunningGTDApp()
if (GTDAppToUse is null) then
  set GTDAppToUse to "OmniFocus"
end if

-- Is OmniFocus running?
on AppIsRunning(GTDAppName)
  tell application "System Events"
    return (count of (application processes whose name is GTDAppName)) is not 0
  end tell
end AppIsRunning

-- If OmniFocus is running, do nothing.
-- If OmniFocus is not running, launch it and bring up the Quick Entry Panel.
on FindRunningGTDApp()
  if AppIsRunning(GTDAppName) then
    null
  else
    tell application "OmniFocus"
      activate
    end tell
    tell application "System Events" to tell process GTDAppName
      keystroke "t" using {control down, option down, command down}
    end tell
  end if
  return null
end FindRunningGTDApp

Like I have stated above, this script assumes that your Quick Entry shortcut is control + option + command + t, like mine is set to. If you want to modify it to suit your needs, simply edit Line 25.