When was the last time you got lost? If you've got a smartphone, it's likely that you'll never again be stuck for directions whether driving or on foot, although your "pocket compass" is capable of much more than replacing your local paper directory.
There are almost half a billion smartphone owners on the planet who are taking advantage of their handset's GPS capabilities.
The technology in an iPhone works by alternating between accessing the 24 orbiting satellites used by all such gadgets, and the nearest web server or cellular mast. It combines that data with its built-in digital compass - which reveals which direction you're facing - and its own maps. It uses this same data to "geotag" all photos taken with the handset.
That's perfect for putting us all on the map, but to what end? Discovering our surroundings is perhaps the most obvious function, and the easiest to control. Smartphones are quickly replacing separate in-car sat nav devices, though they're also quickly becoming useful for finding a suitable restaurant, bar or hotel wherever you are in the world - and that means the death of the guidebook. Lonely Planet's travel apps have been downloaded more than 10 million times, and tourist boards - including Hong Kong's - are beginning to offer visitors some kind of familiarisation app. "The apps are designed for travellers that are already at the destination, thus the planning information is geared for travellers who are on-the-road," says Varsha Dass, marketing executive, Asia at Lonely Planet. "The entire app, including the maps, is fully downloaded onto your device so you can use it offline. It will work wherever you are, and you'll never incur data or roaming charges."
There are similar developments afoot for walkers. It's not about simple map replacement, says Ian Pond, chief marketing officer at hiking app ViewRanger. "It provides a new resource to participants to enhance their time outdoors by making it easier to locate themselves, find trails and hidden places," he says. ViewRanger also allows walkers to share routes and see exactly where each person is. It shares your last known position with rescue teams, if the worst happens. Such apps have also helped popularise the pastime of "geocaching", where GPS is used to locate hidden "treasure" caches around the globe.
A similar, slightly faster-paced GPS revolution is happening closer to home. "GPS has had a bigger impact on fitness activity, where using an app provides the ability to record, measure, analyse and compare performance against personal targets and those of others," says Pond. Budding athletes can now download an app from Nike, Adidas or Endomondo before a run to monitor both speed and geographical progress. They can later instantly upload a complete map of their achievements to Facebook. Adidas, whose miCoach app is available on both iPhone and the Android platform, sells a microchip-endowed "boot with a brain", the f50, which it used recently to calculate the speed statistics and 360-degree movements of Barcelona ace Lionel Messi over an entire match. The tech, which is also sold as Speed Cell, a small tracking device that ties onto shoelaces, teams-up with the iPhone app to deliver not only mapping, but motivational messages in your headphones to keep you running.
Recording your progress is a personal choice, but it can soon morph into semi-sophisticated spy technology. The Phone Tracker app allows you to follow the location of another iPhone user, with "track an employee's movement during work hours" listed as one of the uses.
Of more spiritual worth are GPS apps like Islamic Compass and Kibla! that allow Muslims to find the exact direction of Mecca, and myriad Chinese lunar calendar apps. Stargazers can download apps such as the remarkable Distant Suns, Night Sky and Mooncast, although it's a serious faux pas to whip out an iPhone in the company of astronomers, who despise all white light pollution. Other GPS-enabled apps are more down to earth, with some that show the property prices and even crime rates in the immediate vicinity.
Drivers can already get apps that sound an alert if the speed limit is breached. Coming next could be a "pedestrian detection" system. Using the new Wi-fi Direct standard to communicate separately with surrounding smartphones, General Motors researchers are developing a technology that will enable drivers to see pedestrians and bicyclists. "This new wireless capability could warn drivers about pedestrians who might be stepping into the road from behind a parked vehicle, or bicyclists who are in the car's blind spot," says Nady Boules, GM global R&D director of the Electrical and Control Systems Research Lab.
And for those who wish to collide? The New York City Health Department used last Valentine's Day to launch its Condom Finder app, which quickly identifies the nearest free condom distributor. Who said technology was taking the fun out of life?