I have the AppleScript to toggle the "Ignore built-in trackpad when mouse is present" preference on OSX Mavericks working in the code box below, but I can't keep the "System Preferences" hidden and get the annoying flash as it activates the application window briefly to turn the trackpad on or off. Any thoughts on how I might hide this process? More details below... Code: -- open trackpad preferences tell application "System Preferences" activate reveal (pane id "com.apple.preference.universalaccess") end tell tell application "System Events" tell process "System Preferences" tell window "Accessibility" tell scroll area 1 click UI element "Mouse & Trackpad" of row 10 of table 1 end tell -- click trackpad enable/disable when connected tell checkbox 2 click end tell click button "Show All" of group 1 of group 2 of toolbar 1 end tell end tell end tell tell application "System Preferences" quit end tell Some background: I use my Macbook Pro with Mavericks both with and without an external mouse (a Logitech trackball actually). Both because I hate stray trackpad input as I type and because using only the trackpad can cause me wrist pain after a while, I like to set the "System Preferences / Accessibility / Mouse & Trackpad / Ignore built-in trackpad when mouse or wireless trackpad is present" checkbox to true when using the USB trackball. But because I also like to leave the tiny USB dongle in there, when I don't bother to bring the trackball along I can't easily use the built-in trackpad. So I have been writing an AppleScript to tell System Preferences toggle the Ignore Trackpad setting. That way I can just use command-space to start spotlight and run the ToggleTrackpad script from the keyboard. I am open to other solutions to this problem. I looked into finding a defaults write command for this by seeing if any plist files changed in the ~/Library/Preferences directory, but nothing seemed to change when I ran a diff on their old versions, so I never could figure out where in Mavericks this setting was being stored.