Several keyless entry systems are now catching on in NYC buildings. The app for these systems lets you use your smart phone to gain access to your apartment or common areas such as the gym or amenity spaces. The benefit is that you do not have to worry about giving keys to dog walkers, delivery people etc… and having to track the keys down. Also access to the buildings amenities can be added or subtracted with ease. In our building like many others, we use Building Link which allows you to go online and give/take away access easily. Also, we have finger scanners for storage and our gym which work quite well.
The only potential downside of the keyless system is that you will need to figure out what to do if your phone battery dies but according to the article many of the systems have a keypad and you can just enter your custom code anytime.