We have just looked evil in the face. Its name is iDisplay. Based on an incredibly promising concept, iDisplay purported to extend our Mac's display onto an iPad or an iPhone, over the magic of WiFi. In reality it threatened to destroy our very lives. The application, after installation, tells your computer that it has two displays running concurrently (even when the program isn't open), and limits your main display to a lower resolution -- either with blurry pixels or letterboxing (the latter is shown above). This of course eliminates the purpose of extending a display almost entirely. Add in the fact that we couldn't even get the iDisplay application to open on our Snow Leopard Mac, and we can't imagine recommending this $4.99 combo to a single soul on earth. Even the uninstall process was harrowing. Please, for the sake of your children and your children's children, stay away from this app.
Update: Okay, so we've tried it on a few more machines, and while we managed to make it work in a more reliable way without black bars -- hint, turn off mirroring! -- it's still not particularly usable. Refresh rates are incredibly low, the touch interaction is laggy, and the server app on the desktop is pretty crashy. We really want to love you, iDisplay -- let's work this out, okay?