The software with an unusual name -- Fugawi Touratel -- is Web 2.0-based and can turn different cell phone models into navigation systems with high-resolution U.S. Geological Survey topographic maps, air photos, and urban photos, according to Northport.

Fugawi Touratel also serves up third-party location-based applications, such as U.S. streets maps, for a $3 monthly fee.

The software is compatible with cell phone models by LG Electronics, Motorola, Samsung, and Sanyo, from carriers that include Alltel, Boost Mobile, and Sprint. Northport plans to add support for additional carriers and cell phones in the near future.

Since the software uses Assisted GPS, the phones don't need to have the functionality built in or be connected through Bluetooth. Users can see their actual position on maps, find nearby locations, or use various GPS widgets for outdoor recreation such as hiking, mountain biking, and fishing.

Users also don't have to install client software because Fugawi Touratel works through an Internet connection. The fact that it's always connected to the Web is useful when receiving updates without having to download new software. However, users are likely to encounter problems accessing the application when they have spotty network coverage, especially in remote places.

The demand for location-based services by mobile users and mandates by the U.S. government for Enhanced 911 capability will give rise to cell phones with built-in GPS. GPS-enabled mobile phone shipments will increase from 109.6 million units in 2006 to 444 million units by 2011, according to research firm iSupply. By 2011, 29.6% of all mobile phones shipped will have GPS. As a comparison, only 11.1% of phones shipped in 2006 had GPS.

Even so, Northport isn't the first company to come up with GPS software for cell phones. Garmin in October rolled out Mobile XT, which pairs a smartphone's built-in GPS with Garmin's software to create a full-featured navigation device that can take users to any location in the United States, Canada, Puerto Rico, or Europe. It doesn't require monthly fees or subscriptions and is priced at $99.