Converging Cameras (Toe-in) Parallel Cameras (e.g. Off-axis)
Toe-in cameras Off-axis cameras
The result is not very comfortable to watch: The result is easy to fuse:
stereo output toe-in cameras stereo output Off-axis cameras
look at the lower left and right corner of this image only horizontal disparity of the left and right image


The following is in german but I hope it's easy to understand:


For those who wants to try the 'Toein' Camera Rig,
here is a simple Python script for Blender 2.49b: