The merger of Google Earth, a free app for exploring just about every square kilometer of the planet, and Google Maps is a work in progress. Google used the I/O keynote to trumpet its latest bit of Maps-Earth collaboration. Maps' new Earth View feature, for instance, lets you view cities rendered in 3-D -- a boon to tablet-toting travelers traversing new places. You'll need a WebGL-enabled browser like Google Chrome to use Earth View, however. (Microsoft Internet Explorer 10 doesn't have native WebGL support, but rumors suggest the upcoming IE 11 might change that.) In addition to Earth View, Maps' new Carousel feature provides easy access to the full gallery of Google imagery, including Street View, photo tours and business images.