The iPad has been a good complement to a laptop for a while, but the new Retina display's high quality has us even more excited about the prospect of doing work on the tablet. Touch screen access to photoshop palettes? A second monitor on your laptop at that cramped cafe table? Yes, please.
Turning your iPad into a second monitor is a simple matter of deciding which app to go with and how you want it situated. We've seen a few different apps out there that make the change, each with it's own upsides and downsides. iDisplay ($4.99) will turn your iPhone, iPad or Android device into a second monitor that works in horizontal or vertical orientation. Like most of these programs it works through a wifi connection. Air Display does the same, but it also lets you use a Mac with another Mac or even a Mac with your PC. And while it doesn't have the extensive options of the other two, DisplayPad is the cheapest and one of the faster app options.
Once you've chosen your app you'll have to decide how you want to use your new monitor. Of course there's always your lap, but frankly unless we have zero more desk space we keep it on the table. That being said, we don't want to take up more room than necessary so we like more minimal stands. The Magnus is good when we're using it on our office desks or traveling around as it has a minimal footprint and fits in our bag well. The Apple Smart Cover rolls up and gives bit better angle for drawing with the added benefit of blocking the screen from scratches. And if you're on a tight budget we've heard tell of some people using this $1.99 Ikea napkin holder as a stand for their laptops and iPads.