Facebook's Portal and Portal+ smart displays are now available in the US via Amazon, Best Buy and their own, ahem, portal. The social network created the devices with video chats in mind, giving them AI-powered cameras that can track you as you move around while talking to friends and family. It can call anyone on Messenger, not just someone who also has a Portal, so you can use it to call most people in your friends list. Engadget Senior Editor Devindra Hardawar got the chance to see it in action in October and found that the picture on screen shifted smoothly to keep the person in frame. He said it looked even better in portrait mode -- almost as if the other person were truly in the same room.