I made one out of what was left of an older system (door sensors, motion sensors). Its getting pretty old now as it predates arduinos and was made with a PIC (o

I made one out of what was left of an older system (door sensors, motion sensors). Its getting pretty old now as it predates arduinos and was made with a PIC (olimex PIC with ethernet board). It just posts all of the events from the sensors to a VPS in the cloud (that I have already to run personal web sites). If its "set" with a post from my phone, it simply texts a list of people (wife, dad, good friend) that an "alarm" went off. Otherwise it just records the events for later curiosity. I've also got one IP camera that I can jump on and look into the main room with. It was nearly free except for the happy project time to build it and is all I've ever felt I needed.