Every six months, remote-access provider iPass releases a new Mobile Broadband Index, a look at the stats for its worldwide virtual network of Wi-Fi hotspots. It's virtual because iPass doesn't own it; they use other vendors' hotspots, about 100,000 of them. The index also includes a look at the corporate use of 3G (iPass offers service over EV-DO networks). And, big shock: Usage is up!

From the first half of 2007 to the first half of 2008, worldwide use of Wi-Fi hotspots by iPass customers with an account paid for by the home office--these stats don't include iPass consumer customers--is up 46%. Europe has now surpassed the United States in Wi-Fi use: 47% compared to 45%. The rest of the world takes up that little 8% slice.

Where's the most popular place to use a hotspot if you're a business traveler? Hands down, the airport. Chicago and Atlanta airports have the most users. Hotels are second (but had more growth, perhaps because many hotels are now switching to wireless from their old Ethernet networks). The average amount of time spent on a hotel Wi-Fi session is 40 minutes; in a hotel, it's 2 hours and 47 minutes. Cafes and retail spaces account for only 26% of use by enterprise road warriors.

What about 3G? iPass is offering EV-DO mostly in the U.S. Measurements here indicate a 59% increase in use from last year. iPass also measures the amount of traffic a user generates, and that's gone up from 132MB a month in the second quarter of 2007 to 211MB a month now. A nice indicator that the EV-DO networks (Verizon and Sprint both have one) are growing and size and reliability is that a not only are more users now using it, fewer users are falling back to 2.5G speeds.