I suppose we should send Tim Cook a "thank you" letter for not forcing us to use a 1990s-era serial cable to transfer files between iPhones. However, Apple doesn't believe in NFC or Wi-Fi– direct standards, so forget about transferring files across devices with a tap or activating your stereo by rubbing your iPhone 5 against it.
Like most Android phones, the Galaxy S4 comes with an NFC chip that lets you transfer data or interact with an entire ecosystem of peripherals just by tapping. Samsung's S Beam is by far the fastest and easiest way to transfer data between two phones, as it immediately establishes a Wi-Fi–direct connection between devices.
With NFC, the Galaxy S4 can also connect to Samsung's HomeSync media center and start copying files from your phone. Hold the phone briefly against one of Sony's NFC-enabled stereos or headphones, and music that's playing on your Galaxy S4 will magically start playing on the external device. With NFC, you can even take advantage of mobile-payment services like ISIS (provided carriers get their acts in gear).