I don’t think I ever mentioned here, in the blog, a little hack I enjoyed doing a while back. I bought an old android phone ($10 on eBay, boy was it junk!) and repurposed it to fill the role of an Airport Express, i.e. so I could route music from iTunes to the phone and then to a set of speakers.
Naturally that got me thinking of all the curious things you might do with an Android Phone. For example put it in the car as a nav system, use it as a webcam, or tracking/security device. If you poke around you can file lists of suggestions (for example).
Some of my more self amused fantasies involve using the camera to look at a sensor, say a thermometer for an input signal and then using the flash, speaker, or bluetooth as the output signal in some over engineered control system. Say to boil water, or heat a fish tank.