From a conceptual standpoint, I love the Lockitron; a combination of specially powered lock, an iphone app and some ingenuity. Basically it enables you to unlock / lock your home / office from your phone and share special codes to give friends access to entry as well. That last bit is the real kicker - the key copying industry should be quaking in their boots! The reality of the situation is a little scarier - as you house could actually be hacked for access, or a power outage could prevent you from gaining access on your own.. not to mention the terrible scenario that arises when you forget your phone and lock the door behind you.

Regardless, the concept is rather alluring and I love the NFC version - seems like your house could "see" you coming and unlock itself for you.

Somewhat Related: Start Your Car With Siri