A company in Sheffield, together with contributions from the local Institute of Physics, has built a telescope, primarily out of 3D-printed parts, and used the Raspberry Pi camera module to take pictures through the lens. There’s a little more information on PiKon’s blog and more on the Alternative Photonics site and you can follow them on Twitter.
Andrew Oakley’s daughter’s bedroom is plagued by goblins. So, they decided to use a Raspberry Pi to scare them off! They’ve used a PIR sensor for detection and the Pibrella for a buzzer and general connectivity. Lovely little project – check it out here for a write-up/tutorial with all the code.