For PC Users: DisplayLink (Free)
DisplayLink leverages its experience with networked display technology in the world of PCs with the free (for a limited time) DisplayLink app for iPad.
After downloading and installing the app on your iPad, you’re directed to download and install a piece of software on your computer to handle the connection between the two machines.
Assuming both are on the same network, opening the iPad app will let you select your PC from the list of connected computers, or you can enter your PCs IP address manually. You’ll need to set up a one-time-use password, too, to ensure you don’t connect to someone else’s PC (and vice-versa).
Once the connection has been made, your iPad appears just like any other monitor under Windows’ Display > Screen Resolution settings found in the Control Panel. You can set the iPad’s position and screen orientation for use as a second screen in “extended mode” or simply use it to clone what’s happening on your main screen if that’s more your speed.
The app makes the iPad a great second screen for word processing, e-mail and Twitter use, but it suffers from a fair amount of lag when dealing with any sort of motion. DisplayLink warns that the app is “not intended for 3D PC gaming or use as a primary display for video playback at this time,” though.
Aside from that, it’s a formidable tool for PC notebook users who also travel with an iPad. And the current price—free—is tough to beat, as well.
Check out DisplayLink in the App Store.