However much fun your tablet and computer are when used separately, I like to believe there's a little more fun - and utility - to be had when using these devices together. More often than not, this goal is pursued by synchronising files across platforms, but things get really interesting when you start combining hardware features.

Imagine you could use Mac OS X or Windows on your iPad, combining the hand-held touch interface of a tablet with the raw processing power and extended application capabilities of a desktop computer. Looking at it from the other side, think about using your tablet as an extension of your desktop computer; a portable additional display that fits snugly inside your bag.

Sounds too good to be true? The Air Display app for the iPad proves it's not.

Air Display

Air Display is an application that's available on a variety of mobile devices, including the iPhone, iPad and Android. In this article, we're taking a look at the iPad application, but its counterpart on those other devices works very similar. It should be noted that Air Display works on both Mac OS X and Windows computers.

When you've set up both client and server applications, you can start using your iPad as an external monitor to your desktop computer, or as a singular touch-enabled controller of your desktop operating system. The only real distinction between these two uses is to be found in the display preferences of your computer.

Just as if you would have connected an actual display, you can choose whether to extend or mirror your desktop on your iPad.

Download & Set-Up

Before you're able to use Air Display, you have to download and install the Air Display client application on your iPad and the Air Display streamer on your desktop computer.

The iPad client can be purchased [No longer available] for $9.99 or you can download the free, ad-supported version; there's no additional disparity in functionality. The desktop streamer can be downloaded without charge from the website. It's interesting to note that once you've installed the iPad application, you can use it with any computer that's installed the free streamer application.

The installation of the desktop application will put a helper in your Mac OS X menu bar or Windows system tray. To start using Air Display, open the application on your iPad, turn on the desktop application, and select your iPad from the list of available devices.

Mouse & Keyboard Control

Once up and running, the Air Display application on your functions twofold. You can use your iPad as an external display and use your desktop's mouse and keyboard to manipulate the part of your desktop displayed on your iPad. Alternatively, or interchangeably, you can use your iPad to control your desktop's mouse and keyboard through touch.

Single-tapping your iPad emulates a single click in that area. Similar to right-clicking on Mac OS X, you can right-click by tapping your iPad's screen with two fingers at the same time. At the bottom of your iPad's screen, you'll see a small keyboard which, when pressed, unfolds to the familiar iPad keyboard with added arrow function keys.

Additional Configuration (Mac)

If you're using Mac OS X, Air Display also adds a new preferences pane to your System Preferences, which shows a number of additional options. Most interesting for casual users is the ability to remove the Air Display icon from your menu bar to avoid clutter.

You can also enable or disable touch input from your iPad, and set up your computer to automatically connect to specific device when discovered on the same network. If Air Display running on your Mac, this means your computer will connect to your iPad as soon as you open the Air Display app on your iPad.

What do you think of Air Display's ability to combine your Mac and iPad? Let us know your take on the application in the comments section below the article!