Look who's that
If you are not able to welcome your guest, that have just arrived, use your phone or a TV set. Those devices act when a door bell rings and help you to have a chat with people standing in front of your door. What is the best, you do not have to be home! You just need an access to 3G network. By using 2G you can talk and send photos. Thanks to that, when you are at work, on holidays or do shopping, you have en eye on everything. And if you don't want anybody to know that there is nobody home, this system simulates the presence of the household members! By switching the lights and all electrical devices on and off, it will seem that house is full of people.