Hi guys... To celebrate GDC (or any excuse really), we've got a really nice "little" tutorial for you: Aarku has made a great 2D tutorial -showing you how to constrain Unity gameplay to 2 dimensions. Take it away! http://unity3d.com/support/resources/tutorials/2d-gameplay-tutorial
Way to resurrect a year-old thread! So to be clear, this is nothing new and the tutorial being mentioned was posted a long time ago. But enjoy it as it's a great tutorial and well worth your time.