Toggle Ink's WriteAnywhere with AppleScript
With this script you can toggle the Write Anywhere setting on and off, however it opens the System Preferences in the background:

tell application "System Preferences"
    reveal (pane id "com.apple.preference.ink")
end tell
tell application "System Events"
            tell application process "System Preferences"
                click checkbox "Allow me to Ink in any application" of group 1 of tab group 1 of window "Ink"
            end tell
end tell


I use it for toggling WriteAnywhere from the "Radial Menu" of my Wacom tablet.