I've been using the MotionPi distribution for a little while to turn my Pi Model A into a security Cam. It works awesome. Prior to discovering this disto I was using rasbian and the Python Picamera API, it was excellent for tinkering. and I had it reading from my DS18B20 Digital temp sensor and pasting the results on the camera stills.
I've love this feature with MotionPi, does anyone have an idea how I might implement this?