Orbicule Witness turns your Mac into a motion-detecting home security system. With the alarm set, the application runs in the background and locks your Mac (use your administrator password to disarm).

If it detects movement through your webcam, it records stills and video that can be retrieved through the Witness web page, or using an optional free iOS application.

The iOS app also receives push notifications when the alarm is triggered, and can set or disarm the alarm remotely, as long as your Mac's not in Sleep Mode. An active alarm keeps it from sleeping, but it doesn't stop you reaching it through Back to My Mac.

Any number of Macs can be added to your Witness account, and when you set an alarm, you can exclude Macs.

It only officially supports internal cameras, but third-party cams that work with Photo Booth or FaceTime should be fine. We tried a number of webcams, and they all worked correctly.

Witness is simple to install and use, and reliable in operation. Push notifications are sent quickly, and images and video are stored on Orbicule's servers, so they're still accessible if your Mac's stolen.

There's no option for setting an alarm without locking your Mac, which would be useful for identifying someone who was misusing rather than stealing it, but we're told this feature is coming.

It's Snow Leopard-only, so it can't protect PowerPCs. But if you have an Intel Mac, it's a low cost and useful addition to your home security setup.

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