This instructable describes how to build a surveillance cam based on a Raspberry Pi micro-computer which records HD video when something moves in the monitored area. Live picture can be viewed from any web browser, even from your mobile while you're on the road.
What you will get:
See live stream in any web browser from anywhere
Record any motion into video file
Usually, such a cam will cost you around US$1.000, but with the result from this instructable, you will get such a cam for only about US$120.