InterContinental is about to start allowing guests to unlock their hotel rooms with smartphones. This way, if you put your hotel magnetic card next to your phone, and as a result the configuration is being deleted (as it always happens to me…) – you don't need to worry! You can still use your phone to unlock the door.
Call me old fashion, but I can easily see issues with this new idea: hackers will open other people's doors, smartphones will run out of battery… who knows what can happen?
I think I will prefer sticking with the good old magnetic cards…