What is the use of the "Shape" ?
Well Shapes can be used for all sort of things.... From drawing irregular shapes through to collision. In terms of collision, they can used solo, say perhaps in a custom GUI, where you want to track clicks on irregular regions. Another use is with sprites. Where you can define a shape to outlines the 'hard' areas of a particular image, then when you use this image with a sprite the sprite can use the shape for it's collision checking.
-> Shape Sprite Collision (http://www.underwaredesign.com/forums/index.php?topic=2836.0)
Thank you Kevin