Useful for many things, not only as a grip underneath a camera. It can be used to extend a magic arm and other equipment or to make a homemade / DIY shoulder mount or other things like that.
Full name: Aluminum Alloy 1/4'' Screw Handle Grip Stabilizer for Camera / DSLR + More - Black (7.5cm)
Webshop: DX.com (Deal Extreme)
Price: $10.20 (Free shipping)
Solid material and a nice serrated surface. Convenient with a 1/4' screw hole in the bottom to attach other equipment or for other mounting possibilities.
The grip is a bit too short, I would have wanted it to be around 10 - 12 cm to fit better in my hand. Not sure what the 'Aluminum alloy' material is, it feels heavier than normal aluminum, but it isn't a big deal and the handle is solid.
Buy it here