Non-traditional PLC applications?

Just wondering what applications you've worked on, seen or just thought about that are outside the PLC's traditional domain of industrial machine/process control. I'd expect that the availability of inexpensive PLCs like the Click has opened up wide range of potential uses.

Several home automation applications are discussed in this thread, including irrigation, HVAC and lighting control - even Christmas lights:
http://www.plctalk.net/qanda/showthread.php?t=70711

This thread also discusses an HVAC application:
http://www.plctalk.net/qanda/showthread.php?t=60289

How about hobbies, like model railroading? Or mechanical merchandising or Christmas displays for store windows?

On the Automation Direct board, there was discussion of an interactive game for kids, where they'd race against a moving sequence of lights, and a museum exhibit where visitors would push buttons to activate various parts of a display.

Hello,

My son just got a snap circuits kit and we have been playing every night. He is only 5, (6 next month), and he is really taken a big interest in building electrical circuits. If his interest continues I have thought about getting a click for us to build something cool with, (a ways down the road of course). To your point about affordability, you can't beat the click. Pretty powerful for 70-100 bucks in my opinion.

-Dave

For home I've also seen control of home brewing and aquariums.

For a small controller you might also check out the Arduino.