Steven has made a beautiful suggestions on where to begin or continue in this huge project, In the area he suggested, about GSM home Security alarm system using Arduino. I would be glad to see it multi-task. Apart from sending a text message to the user, I want it call the police and if possible send an alarm. Alarm should be optional anyway. Also, I believe we can improve on it as well by taking pictures of the theft.
Lets see how we can get started as soon as possible. Sharing ideas is good and working together is great.