Travel takes us all over the world, but its key technology battles are happening in your pocket. Mobile use is booming. During 2014, Skyscanner flight searches from hand-held devices have grown by 152 per cent, according to the company. Mobiles will become ever more important, particularly as last-minute and in-destination booking booms.
Gone roaming
Of course, a mobile phone is useless if you can't afford to use it. I have written regularly this year about roaming, including how to avoid charges with apps such as Roamer (Android, iOS; roamerapp.com). Roaming will continue to be an issue, but welcome changes may arrive for European travellers. In April, the European Parliament voted to end roaming charges within the EU by December 2015. Details are still to be confirmed.
The convergence between phone and wallet will accelerate. It is not yet clear when Apple's mobile payments system, Apple Pay, will come to Australia. In Britain, Zapp is working with banks and retailers to add a mobile payment capability to existing UK banking apps. Zapp's service will launch in 2015.
Pay as you go
Some travel apps already have a built-in payment function, including taxi services such as Uber and Hailo and last-minute hotel service HotelTonight. Restaurant app OpenTable (Android, iOS; opentable.co.uk) is trialling payment direct from its app in several US cities, including New York and San Francisco. Set to launch in London, new restaurant app Reserve (iOS; reserve.com) also enables diners to settle their bill in-app. Paying with your phone will become more mainstream in 2015.
Wear it's at
There is already plenty of buzz about "wearable technology", particularly smart watches. The Apple Watch launches in 2015, but Android Wear devices including the Motorola Moto 360 are already on sale. Travel apps will learn how to make best use of this new hardware. For example, clever itinerary management app TripCase (Android, iOS; tripcase.com) automatically notifies a connected watch if your flight is delayed, cancelled or even if the departure gate changes. One of my favourite apps, Rain Alarm (Android, iOS, Windows Phone; rain-alarm.com), also works smoothly with Android Wear. My watch simply vibrates when rain is heading my way. More travel apps will work in tandem with smart watches by this time next year.
Tech-in times
Another sure bet is that hotels will get increasingly tech-savvy. Guests can already check in from a phone with the Starwood SPG and Hilton HHonors apps, for example. Both hotel groups are rolling out mobile phone keys during 2015, so you will be able to walk straight to your room and enter with one tap of a phone. Starwood's iOS app is even ready for check-in with an Apple Watch. Premier Inn's new "tech hotel" brand, hub by Premier Inn , is plans another 10 UK openings alongside its Covent Garden flagship hotel. As well as mobile booking, the hub app controls in-room climate and entertainment.
Joined-up thinking
Separate travel applications can work together thanks to a technology most travellers never see first-hand, the "application programming interface" or API. An API is a set of tools developers use to link complementary services. For example, in the US, Google Maps users can now book a restaurant table directly from the map thanks to an OpenTable API. Users can simply type "nearby pizza" in the Maps search box, read reviews and quickly book without jumping between apps. I can begin to book a taxi from inside the Citymapper transport navigation app (Android, iOS; citymapper.com) if I don't fancy the public transport options. A quest is on to develop the "super app", one that feels like a proper mobile travel assistant, so interest in travel APIs will grow in 2015.
No language barrier
We will also see innovations in some travel mainstays, including Skype. The Microsoft-owned service recently demonstrated its Skype Translator tool, which allows people speaking two different languages to talk to each other hearing simultaneous translation of the conversation. Right now it works on Windows machines between English and Spanish only, but more languages and platforms will surely follow. It's not difficult to envisage how useful a version of that could be on holiday.
On the case
The suitcase has been around for a long time, but "smart luggage" will touch down in 2015. New York start-up Bluesmart has successfully crowdfunded a carry-on suitcase that weighs itself, and which you can lock, unlock and track via GPS from (you guessed it) your smartphone.
So one lesson for travellers in 2015 is this: you had better not leave your phone at home – or lose it either. With everything from boarding passes and train tickets to bank cards and room keys stored on a handset, a pickpocket or mobile virus could seriously disrupt your trip. Apps such as Lookout (Android, iOS; lookout.com) scan downloads for viruses and other malware, and allow you to track or remotely wipe a phone if it is lost or stolen. In 2015, travelling with your mobile secured and close to hand will be one key to a hassle-free holiday.
The Telegraph, London