According to AppleInsider, Near Field Communications reports that Apple has built iPhone prototypes equipped with RFID (Radio-Frequency IDentification).
For those unfamiliar, RFID is either super-convenient, terrifyingly insecure, or both. In a nutshell, it broadcasts a signal that can be read from a short distance to process financial transactions (an easy-pay card), determine identity (some nations' passports), and more futuristic concepts where devices can auto-discover and connect with each other based on their tags.
The convenient part is you could swipe your iPhone to pay for goods or services rather than carrying around cards. Your iPhone could also keep track of tagged item like keys so you can find them between your sofa cushions.
The terrifying part is when hackers and other bad guys read your financial information from a distance, or "see" what country you're from when trying to determine targets in less friendly parts of the world. Or, just use them to track you instead of your keys.
The future is not for the timid, however, so let us know -- do you want?