Twin Cameras

I use two Sony DSC-P10 (5 MPix) mounted on a 48" slide bar as seen in the photos below.
Click a picture for a larger view.

The bottom bar is the slide bar made of 1.5" x .12" aluminum, and the top bar is the shutter release bar made of .38" x .50" x .06" aluminum channel.
The shutter bar is very light weight, and it rests on small silicone bumpers that are attached to the shutter release buttons of the camera.

    The left camera slides on the slide bar.               The right camera is stationary.

The shutter release bar is guided by uprights attached to each camera mounting block.
What is the point of separating the cameras by 46 inches? Answer on next page.
How do you get the shutter release bar to snap the cameras simultaneously? Answer here.