AT&T shared some numbers about its Wi-Fi network usage: AT&T wants to trumpet its Wi-Fi network partly because its included free to what I'd estimate is north of 20m subscribers--a combination of DSL, fiber (U-Verse), business, and smartphone clients. The company said that it saw 15m Wi-Fi connections during Q2 2009 alone and 26m in the first half of 2009; that compares to 20m connections across all of 2008.

Certainly, millions of iPhone users are partly responsible for that, because the iPhone is a peripatetic device, making connections somewhat willy-nilly wherever they're available. AT&T said that smartphone connections accounted for just under half of all Q2 2009 connections, a 41 percent jump from the first quarter this year.

The iPhone 3.0 software will accelerate that trend, because it automatically recognizes and connects to any AT&T hotspot without any additional effort on the part of an iPhone user. That's a neat trick by AT&T to offload 3G data to a Wi-Fi network, reducing congestion in the intersection of heavy availability of Wi-Fi hotspots and heavy 3G usage--city and neighborhood centers.

AT&T said that iPhone usage tripled in June over May, which it attributed to that seamless auto-connection addition to the operating system.