an additional note:
I have used this with the screw from the ball coming out of one of those plastic ebay tripod rings and it worked realtively well an even coming from the tripod screw under the camera. I like that possibility less because the camera then cannot sit flat, but in a pinch - it worked.
Chrisa I see used a different piece of the ball and screw (Chrisa's has the plate), mine on the other hand, is just a ball with a 1/4-20 screw extruding from it. Just a factual difference.
good luck with yours, if you so decide to go in that direction.
They were out of the ball only when I ordered mine so that's why I have the ball with the plate.