Clive Webster has written a tutorial over onexpertreviews.co.uk which uses online service Pushover to send you an alert on your smartphone when your doorbell is pressed. He’s created the doorbell switch with a nice Adafruit button, hooked it up to the Pi and then played the sound of the doorbell from the Pi. It’s an interesting project. Be aware, though, that Pushover is a paid (albeit cheap) service that only works on iOS and Android. Read the tutorial here.
Keep on Truckin'vace117 has taken an old remote controlled truck, ripped the innards out, replaced it with a Raspberry Pi and then strapped an Android phone to the top to provide a video feed. (Yes, he could’ve used the Pi camera, but let’s not hold that against him). He’s then used WebRTC as a web interface for controlling the car. You can see a video below and view the Instructable here. [youtube http://www.youtube.com/watch?v=fUkK5v_VtI0&w=600]
Linux guru Les Pounder has created this fantastic version of Snakes and Ladders called Pythons and Resistors, hooked up to a Raspberry Pi. You press a button to perform a dice roll and magnets and reed switches embedded in the playing pieces and the board trigger sounds to be played if you hit certain squares – the pythons (snakes) and resistors (ladders). It’s a really nice project for which he has provided a complete build-and-code tutorial.