Kayak introduced an Alexa skill a year ago, which lets you search for flights, hotels and rental cars with your voice. Useful, but not that useful -- you still need to hop on your computer or fire up a phone to book them. Might as well do either from the start and use emoji to search for travel deals. Now, Kayak has upgraded its skill, so that you can book a hotel with just your voice. Simple say, "Alexa, book a hotel room in [the location you're going to]," and it will give you a list of available rooms that you can reserve right then and there. The service will make your reservation through its partners Booking and Priceline, but you only need a Kayak account to take advantage of the feature.