This is my serial set, these are easily expandable to handle more bits, but if you do so it requires a bit of tuning on the anti flutter, and the delays. I fixed up older versions in my plots basement, and that is my excuse for the bad lighting, and background junk. I didn't tune the anti-flutter to handle the maximum transmission speed, but it's still plenty fast.

SIPO - Serial In Parallel out
PISO - Parallel in Serial out

The video will give you a general idea of how it works, even though it's a different model.

This video uses it as a control panel
http://www.youtube.com/watch?v=7sWa0U7rRDM

This shows it being used unboxed.
http://www.youtube.com/user/DarkChaw#p/a/u/1/QagLstELXAw