DIY bluetooth door lock

An open source bluetooth door lock,  check out  the step by step tutorial here at Make:

To open the lock, we will use the app LightBlue. It has a section called the Sandbox, that lets you control the LightBlue Bean without having to program your own iOS app. When the LightBlue Bean receives a serial message, it checks the bytes received against the keycode saved inside the sketch. If the keycode matches the buttons pressed in the sandbox, the Bean Lock will unlock or lock. Get the code from GitHub.
Also, remember to add a pincode to your Bean to prevent other people from reprogramming it.

Via Hacked Gadgets.