First Rage Against the Machine, then the Verve -- and now the '90s are really really back, with Thursday morning's announcement that the Spice Girls are reuniting for a world tour.

With an exclamation-filled cheer of "Hey everybody!! We're back!! Can you believe it?!?!," the quintet announced that they've overcome their differences and agreed to roll out the bustiers, hot pants and glittery boots for a world tour that is slated to kick off in Los Angeles on December 7 and hit Las Vegas (December 8) and New York (December 11) before heading to Europe, South Africa, Argentina and Asia in early 2008.

"Who knows if this will ever happen again, it's a once in a lifetime opportunity," reads a posting on the band's Web site, which said that fans who signed up to get tickets would be randomly selected to see "the last chance to dance."

"Imagine you got divorced and you've got back together with your ex-husband," said Ginger Spice (a.k.a. Gerri Halliwell) at the press conference announcing the reunion, which was held at the Royal Observatory in Greenwich, England on Thursday (June 28), according to The Associated Press. "Obviously it's nostalgic. But equally, if new fans want to come along, that's fantastic ... I like to think our songs are universal and they are timeless."

The group member who has kept in the public eye the most, Posh (a.k.a. Victoria Beckham), joked that Halliwell, who left the group acrimoniously in 1998, "just appreciates the fact we've let her back in."

Ginger, Sporty, Posh, Scary and Baby Spice sold 55 million albums during their barely six-year career, which began in 1994 after the members answered an ad in a London music trade magazine. In 1996, the group began a rocket ride to stardom with their infectious hit "Wannabe," which helped their debut, Spice, sell nearly 2 million copies in England in less than two months.

They followed with the Spiceworld album less than a year later, at which point the group had begun suffering a backlash due to dozens of sponsorship deals and a flood of Spice-related merchandising aimed at their largely female teenage fans. A fluffy comedy film, "Spiceworld," was released in late 1997, at which point the group was already showing cracks in its "girl power"-fueled facade.

Just seven months after parting ways with manager Simon Fuller (subsequently one of the masterminds behind "American Idol"), Halliwell quit the group in May 1998, citing internal differences (see [article id="1429890"]"Geri Halliwell On Leaving Spice Girls: 'Love Affairs Burn Out' "[/article]).

The remaining quartet went on to release one more album, 2000's Forever, before disbanding less than a year later. They've remained in the public eye sporadically in the years since, and while none of the solo efforts from the Girls have approached the success of the group, Beckham has become a tabloid staple thanks to her marriage to soccer superstar David Beckham and her fashion choices. Additionally, Scary (a.k.a. Melanie Brown) made headlines last week when paternity tests revealed that comedian Eddie Murphy was the father of her newborn daughter.

According to BBC News, the tour is being put together by Fuller's company, 19 Entertainment. In addition to a greatest-hits album due in November, the AP reported that the group's members will participate in the first official documentary for TV about their rise to fame. "It's going to be the most honest story that you've ever heard," Halliwell said. "You get to see the dark side of the Spice Girls, the gritty side, the tears."

"Girl Power is back and stronger than ever," they promised in the announcement. "What are you waiting for?"