No more rumors. No more speculation. No more false prophecy. For devoted U2 fans around the world, the moment has arrived: The band's tour machine is headed out again, this time for an extended, unbridled bout of "Vertigo."

More than three years have passed since the Irish rock band strode out on stage for its hugely popular "Elevation" tour, which ended in late 2001. The popularity of some groups might wane after such an extended period. But not U2.

If anything, the band continues to cruise at a stratosphere only enjoyed by a select few acts in the course of popular music history.

So what is it that U2 keeps at the forefront of popular music and culture? A resilient link between the band and millions of dedicated fans worldwide.

Despite massive record sales, numerous accolades and the trappings of stardom, the members of U2 (Bono, The Edge, Adam Clayton and Larry Mullen Jr.) maintain a sense of humility born from a deep appreciation for their north Dublin working-class roots.

Even as U2 passed through stylistic phases and a variety of stage personalities over the years - from rebellious activists to self-absorbed rock stars - its members never sought to distance themselves from the outside world. Instead, the group remained firmly grounded, using its music and notoriety to speak out on real-world injustices and the importance of honoring human dignity - issues and themes that not only have resonance, but also have deepened U2's relationship with its fans.

From the first note of an opening song at a U2 concert, the occasion immediately becomes one grand bonding experience between the performers and the assembled. With every dramatic gesture from Bono, with every flick of Mullen's drumsticks, with every power riff from The Edge's guitar or Clayton's bass, the energy of the collective experience builds to a feverish crescendo.

The scene is stirring and intoxicating, if not addictive. it's been this way almost since the band began touring widely more than 20 years ago. And now, as the "Vertigo" tour rolls forward, audiences will once again indulge their unrestrained, visceral exuberance for four middle-aged lads from Dublin.

Here we look at the enduring act from Ireland - its colorful members, recording succes and more.

Click here to download the entire guide to "Getting To Know U2."