DoorBot
Know who's knocking on your door — no matter what time of day — from any place on the planet with the DoorBot ($200). Whether you're just venturing into the world of complete home automation, or you already have your place efficiently networked to a range of devices, this is a great piece to add to your setup. It easily connects to your smartphone or tablet over WiFi, letting you communicate with anyone at your door (from inside your home, at the office, or away on vacation). It features night vision, an adjustable camera angle, a rechargeable battery, and the ability to connect to your existing doorbell wiring.