There are some good apps available for iOS and Android that make it easy to turn your tablet into a second monitor for your PC, but if you’re the type of person who thinks that’s just too easy, here’s a hack for you. Someone figured out a way to turn the Kindle e-reader (not the Kindle Fire) into a second monitor.
This works with both Mac and PC on the regular 6-inch Kindle and the larger Kindle DX (which makes a tiny sliver more sense). It requires jailbreaking the device, which is pretty easy, though does mean you’re testing the limits of your warranty.
The Kindle e-readers sport e-Ink displays with low refresh rates, so why would you want to use it as a second monitor? Well, e-Ink is easier on the eyes for reading. And… I got nothin’. It could still be fun, nonetheless.