Joan Fazio, senior product marketing manager for the Redwood Shores, California-based company, said Chicago’s O’Hare, which is the world’s second largest airport after Atlanta, is also iPass’s principal source of sessions.

In fact, the first seven airports on the company’s list are all in the US: Chicago, Dallas, Minneapolis, San Francisco, Atlanta, Denver and Detroit, with the first non-US airport coming in at eighth, namely London’s Heathrow, followed by Tokyo Narita.

Of course, this may indicate that the US is a more mature WiFi market and that Europe and APAC are playing catch-up. That’s certainly what iPass suggests with another statistic, namely that European access sessions were up 54% in the first half vis-a-vis the same period of 2005. It’s a bit hard to judge how significant that growth really is, however, as iPass didn’t publish a figure for its global access session growth during the period.

However, Fazio highlighted another factor contributing to the growth in iPass’s business during the period, namely the partnerships it struck with The Cloud, KPN, Swisscom Mobile and T-Mobile during the first six months of the year.

The next stage of development will see iPass unveil more alliances with mobile operators. At the moment it offers cellular connectivity with one major US CDMA player (the smart money being on Verizon as Sprint has its own initiative in this context with its Extended Workplace service) and KDDI in Japan, but clearly it needs to offer something similar for major European geographies.

Vodafone would clearly be the operator of choice, both for its breadth of coverage and for the fact that it owns 45% of Verizon, and so would potentially enable some sort of roaming package. However, there are likely to be multiple partnerships, and of course, iPass is already a partner on the WiFi side with T-Mobile.