It sells databases that determine the city, state, and country of Web visitors by using their IP addresses.
Sitebrand's Web-based software helps clients pinpoint the locations of their Web visitors and run location-based promotions with customized landing pages.
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.
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.
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.
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.