Digital Element
It sells databases that determine the city, state, and country of Web visitors by using their IP addresses.
Sitebrand
Sitebrand's Web-based software helps clients pinpoint the locations of their Web visitors and run location-based promotions with customized landing pages.
Skyhook Wireless
Apple used Skyhook's technology for the iPhone. It determines the location of mobile devices using signals from GPS satellites, cellular towers, and Wi-Fi hot spots. Companies can use a program called Loki to track Web visitors' locations using Skyhook's database of 60 million Wi-Fi hot spots.
Where
This platform from uLocate lets companies build GPS-enabled programs that work on a variety of cell phones from many carriers. After people download the Where application, they can use a particular company's widget to, say, find the company's nearby retail stores.
Lightpole
Like Where, Lightpole helps companies develop location-based applications for an array of mobile devices. Trulia used Lightpole to create a mobile application that works on BlackBerrys and several other phones.
Path Intelligence
Using receivers that pick up signals transmitted by cell phones, this United Kingdom -- based company can track customer foot traffic through indoor spaces like malls. Path Intelligence plans to offer the service in the U.S. by next year.
