The idea of locking and unlocking your door is nothing new. The only problem with it is that it isn't widely available to the mass market yet. This may be because of how expensive it is or how temperamental it is. For example what if only your phone could unlock the door but your battery ran out or you lost your phone, you would have no access to your home at all. Finding ways around these problems is vital.
Anywho, check out this video by Lockitron showing the possibilities of wirelessly unlocking and locking your door.