There have been rumors of Google's Chrome browser making its way to the iPhone. This new is huge. Why? Because Chrome is the fastest growing browser in the country. It's not hard to believe iPhone users would want to switch, at least temporarily, from Safari to Chrome once it's available. There's only one problem. Apple won't allow any company to build apps that replace its core apps. That means you can't have your iPhone default to Spotify for music, Chrome for web browsing, or Sparrow for email. Not so with Android. Thanks to the OS's openness you can download any app you want and make it the default.