A photo I played with to create a faux tilt-shift effect (basically, blurring the foreground and background of the photo to create the illusion that the captured image is of a small, make-believe set):
This article will explain how to remove or 'key' green screens or blue screens or remove plain color backgrounds in Photoshop (works with versions 5, 6, 7/CS, CS 2 and CS 3). You might want to do this kind of thing after using your brand-new DIY Greenscreen you just made...