Originally just a Bluetooth speaker with a built-in personal digital assistant, Amazon has upgraded and diversified its Echo family of artificial intelligence products in the past two years, first adding the hockey puck-size version called the Echo Dot, followed by the Echo Plus, which includes home-automation software; the Echo Show, which includes a video screen and can make phone calls; and the latest addition, the Echo Spot, a device with a smaller screen that is something of a smart alarm clock. What each of these devices has in common is Alexa, the built-in smart digital assistant that can answer questions using internet databases as its information source. "She" -- Alexa's default voice is female -- can also read books, play music on demand and engage in a great many other "skills" that users choose on the Alexa smartphone app. Get the full story at Travel Weekly