PHP: Code: Apple chose to force the toggle of scrolling direction for all pointing devices whenever you want to toggle only one of them in the Lion preferences. Many users including myself adopted the new default Natural scrolling for use with their Trackpad but can't get used to it when they scroll with a mouse and would rather have the old, non-inverted scrolling when it's the case. So far, the only way to achieve this without going to System Preferences every time you switch between your Trackpad and mouse was to install Scroll Reverser, a free app that sits in your menu bar and offers you more settings than Lion's default preferences. Unfortunately, Scroll Reverser is very buggy and constantly temporarily switches between scrolling orientations for no apparent reason. I found it to be even more annoying than manually switching the direction in System Preferences. Since there is still no perfect solution to achieve natural scrolling only with your Trackpad without going to System Preferences every time, I decided to make my own using AppleScript and MarcoPolo. Here's a tutorial on how to do it. Natural scrolling only with Trackpad Step 1 : Enabling access for assistive devices To let the AppleScripts toggle your System Preferences settings, you will first need to enable access for assistive devices. To do so, go in System Preferences -> Universal Access and check "Enable access for assistive devices". Step 2 : Creating the AppleScripts You will need to save two AppleScripts: one to enable Natural scrolling, the other to disable it. Open the AppleScript Editor application located in /Applications/Utilities. Paste the following code in it: Code: tell application "System Preferences" activate set current pane to pane "com.apple.preference.trackpad" end tell tell application "System Events" tell application process "System Preferences" tell tab group 1 of window "Trackpad" click radio button 2 if value of checkbox 1 is 1 then click checkbox 1 end if end tell end tell end tell tell application "System Preferences" quit end tell Click File->Save As. Name the file "mousePlugged" and save it anywhere where you won't accidentally move/delete it. I chose my Library Folder. At this point, if you did everything correctly, you could click the "Run" button in the AppleScript Editor and it should automatically open your System Preferences, disable natural scrolling and close System Preferences all in a fraction of second. Now you will need to create another AppleScript with this code: Code: tell application "System Preferences" activate set current pane to pane "com.apple.preference.trackpad" end tell tell application "System Events" tell application process "System Preferences" tell tab group 1 of window "Trackpad" click radio button 2 if value of checkbox 1 is 0 then click checkbox 1 end if end tell end tell end tell tell application "System Preferences" quit end tell Save this one as "mouseUnplugged" at the same location as your last script. If you run it, it should automatically enable natural scrolling. Step 3 : Installing and configuring MarcoPolo MarcoPolo is a freeware that will allow to detect whenever a mouse is plugged or unplugged in order to automatically run the AppleScripts we just made when necessary. Download MarcoPolo from its official website by scrolling and clicking on "MarcoPolo-2.5.dmg (Universal Binary)". Install it by dragging it in your /Applications folder. Open it and an its icon should appear in your menu bar. Click on it and select "Preferences...". Go in the "Contexts" tab and add two contexts named "Mouse is plugged" and "Mouse is unplugged" respectively. Delete the default "Automatic" context. Go in the "Rules" tab and add a USB Rule. Select "Apple Internal Keyboard / Trackpad [Apple, Inc.]", choose the context "Mouse is unplugged", set the confidence at 100% and click OK. Next, add another rule (either USB or Bluetooth depending on your mouse) for the presence of your mouse. Make sure your mouse is connected when you do this step and select it in the list, then choose the context "Mouse is plugged", set the confidence at 100% and click OK. If you have multiple mice (home, work, etc.), add separate rules for each. Go in the "Actions" tab and add an Open action. It will prompt you for a file, go select your "mousePlugged" AppleScript created in Step 2 and click Open. Choose the context "Mouse is plugged". Create a second Open action with your "mouseUnplugged" AppleScript with the context "Mouse is unplugged". You can now close the MarcoPolo preferences. At this point, natural scrolling should be turned off every time you plug your mouse and turned on every time you unplug it. Step 4 : Launching MarcoPolo on startup and hiding the menu bar icon Go to System Preferences -> Users and Groups. Click the on the "Login Items" tab and click on the "+" sign. Locate MarcoPolo in your /Applications folder an click Add. Close System Preferences. If you would like to hide the MarcoPolo icon from your menu bar, click on it and on "Preferences..." and check the "Hide from status bar" checkbox in the "General" tab. MarcoPolo will now be permanently hidden unless you go open in from your /Applications folder. And that's it! MarcoPolo will now be 100% transparent and launch at startup. Natural scrolling will toggle automatically every time you plug/unplug your mouse without requiring any manual toggling.