As anyone who’s spent the night outside their own home in the past two decades can tell you, hotels have been moving away from the whole lock-and-key system, widely adopting keycards as an industry standard.

Now, Starwood, a hotel and resort chain operating more than 1,000 properties worldwide, has been experimenting with some alternative approaches, including a system in which you can open your hotel door with your smartphone.

Here’s the history: Back in 2010, Starwood began experimenting with a Netflix-like approach to check-ins, mailing preferred guests keycards that would be activated when their room was ready for check-in upon their arrival.

Fast-forward a few years, and the chain is now skipping the post office, experimenting with phone-based check-ins at Aloft Hotel locations in Harlem and Cupertino. Rather than getting a physical keycard in the mail, a guest receives a virtual one pushed to her Starwood app, letting her forgo the front desk and use the phone as the room key, connecting to the lock via a Bluetooth connection.

The app works on the iPhone 4s and newer and Android handsets running 4.3 or later; Starwood is quick to emphasize, however, that the front desk isn’t going anywhere, for flip-phone holdouts and Windows Phone owners.

As for the locks themselves, they’re battery-powered. The upside is that they’ll continue to operate should the hotel’s system go down. The downside is that once the battery dies, they’re pretty much useless — thankfully, however, the front desk will get a notification when their juice is running low.

The past year or so has seen a major land rush to produce a so-called “smartlock,” or a lock that connects to your smartphone and can be opened via an app. Within the past few years, products like Goji, August and Okidokeys (listen, we didn’t name ’em) have battled to replace traditional front door keys with smartphones.

It’s an appealing (if potentially risky) proposition for anyone who’s ever fished around for a set of keys on a sub-zero day. And let’s face it: These days you’re a lot more likely to leave behind your keychain (or your hotel keycard) than your smartphone.

You can check out the Starwood keyless entry system in action in the promotional video below:

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