A location based service (LBS) is a data service delivered to a mobile device using information about the device's current location. If you use a smartphone, you've almost certainly used a location-based service. A common example would be a weather application. You click the icon to open the application, and it returns the weather conditions. You don't have input "Lincoln, NE" or "68508" because the phone already knows where you are, and reported those coordinates to the app, so it could deliver the information that is relevant to your current location.
Many mobile devices these days are location aware. There are a few different ways a gadget can figure out it's location. First, if it is a phone or has a wireless air card, the cell phone signal includes some location data. Your cellular carrier knows what tower the phone is communicating with and where that is located, and in some circumstances your location can be triangulated even more precisely because your cell signal is pinging multiple sites. Second, if the device uses WiFi to connect to the Internet, WPS (wireless positioning systems) could be used to determine it's location. WPS providers maintain large databases of the locations of Inteternet access points. Finally, the current crop of smatphones, many tablets, and a sack full of other gadgets now have integrated GPS, hence the ability to determine latitude and longitude by the signals of global positioning satellites.
There are tons of LBS applications available for the new generation of smart phones and tablet computers that are taking the mobile computing world by storm, and these kinds of apps have widely adopted by consumers. This is how tens of thousands of people will find restaurants, bus stops, dry cleaners, and nearby ATMs today. It is remarkable how quickly LBS apps have become integrated into the daily life of so many people. The increased computing power of mobile devices, the falling price of GPS receivers, and the proliferation of broadband data services has changed the landscape of mobile computing dramatically.
Location-based services have tremendous potential in criminal policing, emergency services, and community corrections. I have a feeling that we're on the verge of something significant in these fields. More on that later this week.