T-Mobile Hotspot, the public Wi-Fi operator branch of T-Mobile USA, announced several new roaming partners that expand its Wi-Fi coverage both in the U.S. and internationally. The company also announced that more than 450,000 customers have paid to use its network of public Wi-Fi locations in the last 90 days.

Among the new partnerships, an agreement with iBAHN (formerly STSN) expands T-Mobile Hotspot service access into 525 hotels. In addition, agreements with Concourse Communications and Opti-Fi will allow T-Mobile to add hot spots in 39 airports to access locations in a total of 72 airports in North America.

New international roaming agreements with Orange France, Swisscom Mobile, Portugal Telecom and ePLDT in the Philippines will allow T-Mobile Hotspot subscribers to roam in 9300 new locations, boosting the number of T-Mobile Hotspots and roaming locations to 25,000 worldwide. About 12,200 of those are branded as T-Mobile Hotspots, with the rest through roaming partnerships.

"We're seeing something similar to the early days of cell phone usage, where companies are working out the roaming relationships and the integrated billing [to make usage easier for customers]," said Mark Bolger, director of brand marketing at T-Mobile Hotspot.

In addition to the new partnerships, Bolger said the company's 450,000 customer sign-ups in the last 90 days was evidence of a market "inflection point" for public Wi-Fi, which "has become more mainstream more quickly than some people had anticipated."

Bolger also released other statistical information about the service, including that about 40% of T-Mobile Hotspot users also are T-Mobile cellular customers, adding an average of $20 additional revenue per customer monthly. Also, T-Mobile Hotspots transported 17.5 terabytes of data during the month of May, about 7.5 more than in the month of December 2004, a tremendous increase in traffic, according to Bolger.

In addition, T-Mobile Hotspot users now stay online an average of 64 minutes per session, up from about 45 minutes per session last year, evidence that Wi-Fi is starting to become much more of a "lifestyle service," Bolger said.