I got this idea from flickr (not sure who the photographer was. I saw it a while back.) I like it because it can represent so many things, depending on how you wish to look at it. For example: it could be kids raising hands in class, someone trying to block the sun light, worshiping, sinking, reaching for help, wanting to be held, etc.
To take this shot I hung a white piece of cloth over the door frame. I used a halogen light on the bathroom counter behind the cloth. Set the camera in the hall on a tripod. set the settings and the timer. Then ran behind the curtain and posed. Then I played around in picnik and here you go.