It was one of the biggest tech headlines of the year: in September, Apple dropped its contract with Google, which had always supplied the data for the iPhone's Maps app. As everybody knows by now, Apple got lost along the way. Timothy Cook, Apple's chief executive, publicly apologized. Meanwhile, rumors swirled that Google would create an iPhone app of its own. Now, Google Maps for the iPhone has arrived. It's free, fast and fantastic.The first great thing about Google's new Maps is the underlying data. Hundreds of Google employees have spent years hand-editing the maps, fixing the thousands of errors that people report every day. (In the new app, you report a mistake just by shaking the phone.) And since 2006, Google's Street View vehicles have trawled 3,000 cities, photographing and confirming the cartographical accuracy of 5 million miles of roads.And then there's the navigation. Lots of iPhone owners report that they've had no problem with Apple's driving instructions, and that's great. But I've been idiotically misdirected a few times — and the trouble is, you never know in advance. Google's directions still not always perfect. But after years of polishing and corrections, they're right a lot more often.