The Consumer Electronic Show, sprawling over five massive halls here in Las Vegas, is full of giant televisions, sound systems, appliances, and more connected gadgets and products than any one place can host. All of it is trendy — bright, loud, and aimed to grab you — but much of it isn't at all pragmatic (a 170-inch SUHD TV anyone?), and hardly worth a second glance. That's where we come in. Here, from the floors of the show, are the items that are truly groundbreaking, in the sense that you'll want one, stat.