TapRoot Systems today commercially launched its WalkingHotSpot client, a potentially disruptive application that can turn a WiFi-enabled smartphone into a miniature WLAN router that uses an operator’s 3G network as backhaul.

Launched as a beta application at CTIA Wireless last spring, WalkingHotSpot uses the WiFi radio in Windows Mobile and Symbian OS smartphones to establish direct data connections to other WiFi devices such as laptops, digital music players or PDAs. It then connects those devices to the Internet through the phone’s 3G chip, essentially using the smartphone as a WiFi hub and the 3G network as a broadband connection. The result is consumers with an unlimited smartphone data plan—which often run as little as $20 a month in the US—can create a personalized hotspot on the fly from almost any location.

North American carriers have traditionally been cautious about letting their 3G networks be used for wide open data-access, charging higher rates for data card plans or tethered smartphone-as-modem services. But the TapRoot application allows users to bypass many of those restrictions. Despite the disruptive nature of WalkingHotSpot, TapRoot officials said that the application has received encouragement from operators in North America, Asia and Europe it has spoken to about the platform.

“In quite a few cases, we’re being told to roll this out to validate the market,” said Mike Lindstrom, vice president of carrier solutions at TapRoot. “If there is an uptick in data usage, the carriers will see revenue generated in new data plans and more use on existing data plans.”