I have read most of the topics here.. Consider this simple solution. I have an insteon camera pointed at mt front door with a mic and speaker connected to it. I also have a button (doorbell button)connected to my insteon system that sends me a sms when pressed. I can initiate a one way video conference with the guy at the door with the camera. One way meaning I can see him but he can not see me. Who knows I may be in my underwear!