Question: I'm planning to make DIY Home Surveillance. Now I'm looking for free motion sensor. I'm using webcam as a camera to detect whether there's a motion changes in my house. Does anyone know what is the best free motion sensor software? Also I want the software emailed me if someone tried to breach my house. 
Currently I'm using PC with Windows as its Operating System. 

Thanks

Answer: 
here is a nice DIY tutorial:

[How to use your PC and Webcam as a motion-detecting and recording security camera](http://www.simplehelp.net/2006/09/27/how-to-use-your-pc-and-webcam-as-a-motion-detecting-and-recording-security-camera/)

and here's a specialized shareware program ($25):

[**SupervisionCam**](http://www.supervisioncam.de/) captures and compares images from video cameras at intervals you define. It starts optional activities when a movement is detected.
If you use Linux, I know there a packages that does what you want. It can even email you with the video where something moved