Orbicule has released Witness 2 for Mac OS X 10.6 or higher. It’s an update of the software turns a Mac into a home alarm system, using its iSight camera as a motion sensor. If motion is detected, Witness sends mugshots and video to your iPhone or iPad.

Witness uses advanced motion detection, says Peter Schols, president of Orbicule.. The alarm system can be controlled and monitored remotely using either the witnessapp.com web app or a free iOS app. These apps allow the user to remotely arm or disarm the alarm and they instantly alert the owner when motion is detected, showing mugshots and video of the intruder.

Witness 2 adds auto activation, face detection, motion detection sensitivity, support for multiple cameras and AppleScript support. There’s also a new Sneak Peek feature via which you can watch live images from any Mac in your alarm system on your iPhone or iPad.

Witness is available from http://orbicule.com/witness . An account costs US$39 (one-time fee), with a $29 student license. Version 2 is a free update for registered users.