March 31, 2010, 11:48 AM — Facebook wants to know "What's on your mind?" Twitter asks "What's happening?" But that's getting old already. The burning question for the next wave of social networking is "Where are you?"--and services like Foursquare, Gowalla, Brightkite, and Loopt want you to use your smartphone to answer it.
The technology at the heart of this trend is called geolocation; and with a GPS-enabled smartphone such as the Apple iPhone, Google Nexus One, or RIM BlackBerry, you can use it to let your friends know where you are, or to find places recommended by people you know, or to check in remotely at clubs, bars, and restaurants. Regardless of privacy concerns (which I'll look at later in this article), it looks as though nothing will stop geolocation.
How It Works
Typically, geolocation apps do two things: They report your location to other users, and they associate real-world locations (such as restaurants and events) to your location. Geolocation apps that run on mobile devices provide a richer experience than those that run on desktop PCs because the relevant data you send and receive changes as your location changes.
Smartphones today have a GPS chip inside, and the chip uses satellite data to calculate your exact position (usually when you're outside and the sky is clear), which services such as Google Maps can then map. When a GPS signal is unavailable, geolocation apps can use information from cell towers to triangulate your approximate position, a method that isn't as accurate as GPS but is has greatly improveds in recent years. Some geolocation systems use GPS and cell site triangulation (and in some instances, local Wi-Fi networks) in combination to zero in on the location of a device; this arrangement is called Assisted GPS (A-GPS).
As long as the sky is fairly clear, the geolocation app on your phone can ascertain your position reasonably accurately. Indoors, however, it's less accurate, and in locales where storefronts are in very close proximity, you may have to select your location manually from within the app interface.Eventually, though, more-advanced A-GPS systems should increase the accuracy of geolocation positioning inside buildings.
The First Wave of Apps
Several start-up companies offer geolocation services--and some, such as Foursquare, reach hundreds of thousands of users. Not only do these services let you share your location with your friends, but they also bring a social gaming element to the table. Let's have a look at some of them.