There are moments in one's professional life when you have to let out a big burst of air you've been holding in. I just let one of those out.My first business feature appears in tomorrow (Monday's) New York Times, focusing on a Wi-Fi hot spot builder and issues related to offering broadband service in business locations. I started writing as a freelancer for the Circuits section of the Times back in 1998, while nearing the end of treatment for cancer. My first piece, just over five years ago, was about using the Internet to research the disease that I had fought. (And won!) Over the last five years, I've written a variety of Circuits pieces: more features longer ago, and more blurbs and short articles lately, as the advertising crunch took pages away from the section, putting more emphasis on staff writers. I've also been writing very wee (50 to 200 word) business briefs for a summary called Technology Briefings that runs Tuesday through Friday in the business section. Because of my interest in wireless networking, those tend to revolve around Wi-Fi announcements: I've written four or five in the last few weeks about McDonald's, Marriott, and others. The piece that appears tomorrow and is online tonight was weeks of work, lots of interviews, many drafts, lots of sweat. I wanted to nail the subject matter and the numbers. I believe I did so, but I'm sure my email box tomorrow will tell me what others think of the job I did.