I found this project on TechCrunch written up by John Biggs. Read the entire article on his website for all the related comments, articles and fun stuff. I am simply saving it here to copy it to a maker I know with an Arduino.
Say you’re a misanthrope and you’re afraid of humans. What to do? Well, you could cower in the dark when people ring your doorbell or you could laugh derisively at their smug faces in the screen of your iPhone. I’m going for the derisive laughter.
The system works by pushing images grabbed by the webcam through PushingBox to an app like Prowl or Pushme.to. When the doorbell is pressed, it sends a serial signal to the Arduino board which in turn notifies the various services. The webcam picture then gets sent over to you so you can decide whether to let whoever is outside in.
It’s probably a little more complex than it needs to be, but if you’re totally into watching the world pass you by it’s a great solution and a fun weekend project.