Boasting a host of everyday functions, smartphones are the modern day Swiss Army knives. They’ve replaced our watches, books, travel passes and loyalty cards. And now, De La Rue – the British printer of secure documents and banknotes – is working on a way of adding your passport to that list.

Don’t you just hate it when you’ve gone out for the night and as you approach your destination you notice that you’ve left your ID at home? As smartphones contain increasing amounts of personal information and are rarely out of reach, could they make this issue a thing of the past?

Australia's Seamless Traveler initiative is taking border control into the 21st century, with paper passports giving way to facial recognition technology. But given the high-stress atmosphere of airports, they might not be the ideal place to iron out the kinks of error-prone technology.

With $385 billion currently invested in global airport developments, lounges and runways are changing rapidly. It might be decades before ‘airport cities’ are developed, but we’re already seeing new outdoor spaces, retail opportunities and better logistics. What does the future of airports hold?