Near Field Communication (NFC) is becoming more popular recently. Google has recently put NFC chips in its smartphones and has built NFC capabilities in the latest builds of Android which lets users pay for goods by using their smartphone as a digital wallet. It now appears that Yale, the lock company, is also beginning to push the technology.
Yale has created an NFC based door lock that allows you to use a smartphone to unlock a door. The lock is completely standalone and doesn't require it to be connected to anything other than being fastened to a door of course.
When loading up an app on a smartphone you can then choose to lock or unlock a door by selecting an option on the screen. It isn't clear if this could be easily integrated with a network connected door although this specific lock isn't connected that way, we could also see similar locks in the future that can let you unlock remotely.
Take a look at the video below to see it in action. The app looks a bit clunky, but it seems like early days for this at the moment.