And here we thought San Franciscans only lined up for new Apple products. The scene outside Bill Graham Civic Auditorium this morning outmatched the fervor of any iPad release - complete with drag queens in school girl outfits, gaggles of bubbly tweens and of course, a solid gay fan base, many of whom had camped out overnight to secure a good viewing of Britney Spears' highly-anticipated free concert. The show, which was originally slated to go down in front of the Castro Theatre but was canceled last week due to rain concerns, sold out in less than 14 minutes as a ticketed event. 

The bonanza was a promotion for Britney's new album Femme Fatale -- and this morning, she sang (lip-synched) and shimmied to three of her new songs ("Hold It Against Me," Big Fat Bass" and "Till the World Ends") for the Good Morning America cameras, which were taping the whole affair to be broadcast on next Tuesday morning's show. Brit's a little careful on stage these days, always looking a bit afraid she's gonna fall (legitimate concern). But she and her fem-bot body suits were looking pretty good -- and did some convincing hip thrusts and confident side-stomps amid an army of 1,000-calorie-a-move backup dancers, explosions and hair blowers. Overall, she put on a pretty exhilarating show. "Till the World Ends," the last and best song she performed, is a seriously pump-ed up party anthem, and is no doubt on repeat at one of the many Castro after-parties this afternoon.

It was a carefully orchestrated television event for GMA - and heavily make-up-ed hosts Robin Roberts and Sam Champion came on and off the stage between  songs to gather soundbites for the show. At one point, Roberts teased to the cameras that Britney had made a "major announcement" to her backstage. She obviously couldn't blow the news before the show aires on Tuesday, so we'll have to tune in next week to see what it is. Bets?

Photos by Misha Vladimirskiy