From Green Screen Wizard:
Green Screen Wizard is powerful green screen software for photographers that is inexpensive and simple to use. Green Screen Wizard Photoshop PlugIn wraps the Green Screen Engine in a Adobe Photoshop PlugIn interface. The advantage of using Green Wizard inside of Photoshop is that you can take advantage of all of the Photoshop editing capabilities. In addition Photoshop can read and save many more file formats than Green Screen Wizard standalone.