With ShareMouse for Mac you can seamlessly share a single mouse and keyboard between multiple computers on the same network. If you are willing to buy the full version, you can even drag and drop files between computers, enable sharing on more than just two monitors, and prevent accidental monitor switching.
Doesn't require device pairing: Once the cursor is on one screen, the shared keyboard will also function for that screen. With ShareMouse for Mac there is no need to pair or unpair Bluetooth devices.
Works seamlessly: When you drag your cursor to the edge of one screen it automatically jumps over to the neighboring monitor. This app also allows you to share the clipboard between computers, which means that if you "copy" something on one screen, you can use the keyboard to then "paste" it onto a document open on your other screen.
Mac OS X and Windows cross-platform support: This application allows you to control a PC from a Mac and vice versa.
Cursor a bit slow on second monitor: We noticed absolutely no difference between the functionality of the keyboard between monitors, but the cursor did respond with a very slight lag once it crossed over to the second screen. We noticed this both when using our iMac's magic mouse on our MacBook Air's screen and when using our MacBook Air's trackpad to control the cursor on our iMac's screen. Although this change in responsiveness was noticeable, it was not significant.
If you are working with multiple computer monitors on a regular basis, you should give ShareMouse for Mac a go. It's easy to navigate and besides, it comes with a detailed, helpful user guide. While you must purchase a license to take full advantage of some of this application's features, it's definitely a program that can increase your productivity.