This is the page that allowed me my “Eureka” moment on how to drive a large number of outputs from a very few number of pins.  If you ever wished you could have 10 or a 100 more output pins – the shift register chips are ones to consider.  I won’t blabber on just follow the link watch the video and you know where to start if it can be applied to your own effort.

http://bildr.org/2011/02/74hc595/ 

Enjoy