To make this work, install Motion on a system running Linux. As its name suggests, Motion is a free motion-detecting application that monitors movement in a webcam’s field of view. Once installed, it should be configured to take a snapshot of the event whenever something moves; with the locate option turned on, it draws a square frame around the area where motion occurred. The program includes http server functionality, so the photos can be viewed from a remote location. When all of that is properly configured, motion can be set to trigger cURL, Wget, or [Goel]‘s Perl script to post a message to Twitter about the event. From there the Twitter account can be configured to send text messages to a phone, creating a virtually instant notification of motion sensed by the webcam.

[via Hackszine]