I recently purchased a Lytro Illum camera. This camera is much father from my goal of a DIY Stereo camera, but it provides some interesting features I think are worthy of talking about. The Lytro is a light field camera, meaning it doesn't just capture a 2d image, but captures both the "normal" data of color and intensity as well as adding another piece of information, direction. This lets the camera do many of the features of stereoscopic cameras with a single sensor!

This is pretty incredible as it allows 3d photos from a single lens and eliminates many of the calibration issues of a stereo camera. It does cause other issues, in that you're relying on highly technical work done by other people and can't get to all the data. Lytro does have some very open scripts (written in python) that let you do a lot of things with the camera and it's data, but I'm still checking all that out.

In general, Lytro is not going to be the answer for a DIY camera, but it's useful to see what the different technologies let us do.