Ycombinator-backed Lockitron aims to replace physical keys entirely by letting you control your door lock with your phone. The Lockitron web app and hardware package are as of today available for general users, for a one time fee of between $295 to $500.
Instead of using relatively unreliable wifi, the service works by utilizing a plug server and ethernet cable tied to an electronic lock. Your smartphone talks to the server controlling the lock via the web which means that you can control the lock from wherever you are. Lockitron also has an NFC option if you’ve got a Nexus S or are planning on buying a iPhone 5 if/when NFC happens. The system works with both deadbolt and handle locks.
While the Lockitron locks do accept traditional keys, the main advantage of using the same technology as found in car key fobs to open your front door is that everything is in the cloud (your data is encrypted). With Lockitron you can create multiple “keys” and pass them around to friends via email. You also no longer have to worry if you’ve locked your apartment in the morning, as you can just control the lock from your phone.