The biggest discotheque in Las Vegas

     The big show is tonight. But some fans didn't want to wait that long.
      The worst-kept secret in town is that U2 has been rehearsing its "PopMart" tour at Sam Boyd Stadium for the past week and a half. As today's show drew closer, more and more fans gathered in parking areas south of the stadium for a sneak preview of the big show.
      While some neighbors beg to differ, having the band in town for an extended stay only adds to most fans' excitement about the yearlong tour launching in Las Vegas.
      About 30 cars were parked south of the stadium by 7:30 p.m. Thursday. About an hour later the strains of the late-'70s hit, "Pop Muzik" blasted loud and clear over the end-zone wall.
      Fans such as Roger and Roland Campos, two brothers attending UNLV, said that staking out the parking lot on previous nights yielded such highlights as the band goofing on bits of "Smoke on the Water" and "Stairway to Heaven", or lead singer Bono messing up the words to the band's current single, "Staring at the Sun."
      "I did hear Bono cussing. He was very upset," said Minerva Nilsen, of San Diego. She and husband Chris had a microphone wrapped in a towel poking through the sunroof of their car, leading to a portable DAT recorder inside the car.
      The Nilsens were among the brave few who also weathered Wednesday night's wind-and-dust storms.
      To the west, Angie and Stefan Hartwig, who had just finished a 30-hour drive from Sioux Falls, S.D., were among five friends munching down Taco Bell food. "We ran into storms and accidents," she said.
      "It was worth it, at least we assume it's going to be," he added.
      Security personnel were tolerant of the party which included lawn chairs, coolers of beer and cell phones for their friends to hear the band. The only time officials interceded was when people tried to follow limousines out of the rehearsals.
      "Las Vegas being the sort of city it is, we're not really the curiosity to the extent we would be in other cities. There's enough spectacular competition here," tour manager Jake Kennedy said of the set-up's relatively low profile last week.
      The band rehearsed in an indoor room backstage each afternoon -- "to protect our delicate Irish skin," Kennedy said -- before going onstage for longer rehearsals at night.
      Volume levels from rehearsals have drawn some complaints from nearby residents.
      Most calls have come from the Stadium Mobile Home Park, which sits almost next door on Russell Road. But residents reported noise and vibrations from as far as the Emerald Valley subdivision, nearly three miles to the southwest near Stephanie Street and Warm Springs Road.
      "It wouldn't be so bad if you could hear what they were singing, but it's just a `boom boom,' like a car stereo," said Tamara Williams, who lives more than a mile southeast of the concert site, near Boulder Highway and Sunset Road.
      Pat Christenson, director of Sam Boyd Stadium and the Thomas & Mack Center, said the production crew agreed to end rehearsals by 11 p.m. He said the sound "had to be corrected at the concert level" to be effective as a rehearsal.
      "I don't want to play (the noise complaints) down, but we're getting a lot of calls from the same people," Christenson said.
      Christenson cited the economic impact of a tour that brings a production crew of about 250 people to town, with 200 more locals hired to work on-site.
      While the band did not arrive until April 15, the stadium was rented for 30 days, and the University of Nevada, Las Vegas -- which operates it -- stands to net about $300,000 from the concert, Christenson said.
      Christenson also estimates that 7,000 to 10,000 tourists will be among the sold-out crowd of 38,000, and that Las Vegas will be promoted through concert coverage on MTV and an hour-long ABC special that airs Saturday ("U2: A Year in Pop," at 10 p.m. on Channel 13, KTNV-ABC).
      "This is the highlight of our year at the stadium," Christenson said.
      "Our goal is not just to get someone in our facility, it's to bring them back," he said.