A variation of this adapter can be found at Orion Telescopes. It is under their camera adapter section and is called the SteadyPix Universal Camera Mount.
FInd them at Orion Telescopes. Their adapter can be found at this link. (9/17/2007). The adapter has a price of $37.
A newer version of the original EZ pix has been released y ScopeTronix and is called the EZ Pix II. It is sown in the second set of photos attached to the microscope and attached with the Coolpix camera,
It uses a pressure ring to attach to a lens barrel (like the EZ Pix Universal) but then employs a cross screw mechanism to position the camera.
Two adjustable screws are mounted below the platform that holds the camera and be positioned with great accuracy. Micro adjustments are very easy with this mechanism, but if you use more than one camera body the adjustments can be slow as turning the screw takes time for larger movements.
both systems work about equally well with my scope. The EZ Pix II is more rigid and bit more expensive. It can be found at ScopeTronix (look at Digital Camera Adapeters) for about $100.