Apple has let loose iOS 7.1 -- you can update your iPhone, iPad or iPod Touch by going to Settings > General > Software Update to get it, though if you're like me, you'll have to clear out a whopping 2.5 gigabytes of priceless baby photos in order to make enough room to unpack everything.
Assuming you do, you'll be able to integrate your iPhone with your car via the new CarPlay interface (you'll need a car that has a CarPlay-compatible entertainment system, of course, which won't happen until later this year). There are also a couple Siri-related tweaks, some iTunes Radio-related updates, some additions to the Calendar app, some new Accessibility options, and a handful of other nips, tucks and bug fixes. Check out Apple's iOS 7.1 page for more info.
iOS 7.1 Update [Apple.com]