Kar keys have been a rapidly changing concept in the auto industry over the last several years. From keys to chips to proximity sensors, the next key fob will actually be the driver's own smartphone.

Hyundai recently revealed their idea of making a smartphone app that can start, unlock, lock, and perform a variety of other tasks to a person's car. The "digital" key can be shared with four other individuals, allowing everyone in the family access to a vehicle. Access can also be limited to specific times or durations and notify owners when the vehicle reaches certain speeds or leaves certain areas, a common choice for parents wanting to monitor their children's driving habits.

The smartphone app used to facilitate the digital key will also remember each driver's personal settings. This includes seat and mirror positioning, preferred temperature and audio settings, and common navigation locations.

Hyundai intends to introduce support for this technology in new cars starting later this year.

As cool as it seems, I'm not sure how I feel about my car access being limited to when my phone has battery.