I use this lock for my short term vacation rental properties:
http://www.schlage.com/en/home/produ...ctronics/zwave
It is pretty much a for managing who has access to my properties. I set codes for renters from their check-in dates to check-out dates and the lock takes care of automatically adding and removing their codes. I set up temporary codes for repair-men and delivery men. I also get e-mail notifications when someone enters a code. I can also lock the door from Calgary if a renter forgets to lock the door after
It is based on the home automation protocol called Z-wave. All you need is a Z-wave receiver and connect it to your router. Different receivers have different software and capabilities, but almost all require a subscription fee to use it over the internet. There are other z-wave products like light switches, motion detectors, smoke alarms, thermostats, garage door openers.
You can program the z-wave products to do things based on triggers. For example, you can program your lock so that when your wife enters her code to come home, the front hall light (controlled by a z-wave) switch comes on and sets the thermostat to her preferred temperature.
The system is not perfect though. Some Z-wave devices are incompatible with certain z-wave receivers and some software leaves a lot to be desired.