In the future you will be able touch a door to unlock it.  Wait, that time is now.  Kwikset has released the KEVO Bluetooth deadbolt. The lock looks and works like a traditional lock except is has Bluetooth technology inside.  What this means is you can open your door just by touching the lock as long as you have your smart phone or the included key fob with you.

The app needs to be open on your phone for it to work.  Install is just like any other deadbolt install.  You can easily re key the lock to match your current house keys.  When you first set it up you need to calibrate it.  This ensures that the lock does not open when you are sitting inside your house. It knows where you are.  Check it out via Amazon.