Every once in a while you just have to step back and admire how quickly wireless LAN technology is taking over the world. In the last couple of weeks, Network World has happened to run several stories that illustrate the trend very nicely.We recently saw San Francisco take steps toward establishing a municipal Wi-Fi network, accepting six vendor proposals to build a wireless network to extend \u201cuniversal, affordable\u201d Internet access to all good citizens.Meanwhile, Atlanta\u2019s airport has been busy installing an airport-wide WLAN (which went live in October) and extending cellular networks throughout the airport more recently. The latter project uses distributed antenna systems to ensure clear cellular signals over a 6 million-square-foot area.I remember that just a few years ago airports actually frowned upon cell phone use on their premises because it took away from revenue from pay phones. It seems Hartsfield-Jackson Atlanta International, at least, found a way to make money from the tidal wave of cell phone use, rather than get in the way.In Tempe, Ariz., metropolitan WLAN services and cellular data services exist side by side, and there is actually choice. As my colleague John Cox writes, you might use one or the other or both. And this is a choice that more folks in more communities will have.Finally, Network World this week takes a look at the bigger picture, noting that in two years we have gone from zero to about 320 communities that have or are planning broadband wireless networks. The story examines why and how the communities are going this route so quickly.