Here’s a fun, kinda crazy way to use the sudden motion sensors that come in some Mac notebooks, like the newer unibody MacBooks and MacBook Pros. These sudden motion sensors are used by Apple to detect when a laptop with a physical spinning hard drive is dropped, and therefore this tip won’t work on the 2010 or 2011 MacBook Airs that shipped with flash-based, non-spinning SSDs. Using a third-party app, you can pick up your laptop and give it a shake-to-undo option, just like the one on your iPhone, iPad or iPod touch.
The application is called Shake To Undo, and you can download it here or by visiting the official GitHub site. One you have a copy, you’ll need to install it. Just open the DMG file you downloaded and drag the application to the Application folder on your Mac. Locate the copy in that folder and double-click to open it.
Shake to Undo will start and show up in your menu bar. From there, you can toggle an option you might find useful. It is called Confirmation Overlay and it will prevent you from accidental undos if you simply move your Mac notebook. When active, this feature causes the application to prompt you with a confirmation dialog to clarify whether you want to clear or undo text you just entered.
Although this tip can be a lot of fun, I recommend you don’t get carried away and shake your Mac too hard. Apple might not be too happy with you when you show up at the Genius Bar with a laptop suffering from Shaken Baby Syndrome!