It may be one of the first airport amenities specifically designed for cell-phone users: In light of the security changes at Denver International Airport that eliminated the 45-minute free parking spots in the passenger pickup area, airport officials have designated the old toll-plaza area (torn down last year when the booths were relocated closer to the airport) as a new free 45-minute parking lot. (Of course, people have been using the area illegally for a while, despite signs that warn motorists against stopping.) Since the seventy-space lot is four miles from the terminal, however, arriving passengers have to use their cell phones -- or a pay phone -- to call friends, relatives or associates who are waiting in the lot with their cell phones. Still, it's a creative, and helpful, use for the old space. Ring up a winner.