What do Lance Armstrong, John Mayer, and Mary J. Blige all have in common?

They all own iPods, and they all were willing to shill for the vaunted digital media player in today's announcement that Apple has sold the 100 millionth iPod.

The milestone comes five years and five months since the iPod debuted in late October 2001. Since then, Apple has introduced more than 10 new iPod models, including five generations of iPod, two generations of iPod Mini, two generations of iPod Nano, and two generations of iPod Shuffle.

Mayer, who performed at the iPhone announcement at MacWorld in San Francisco in January, offered up his endorsement in a statement.

"Without the iPod, the digital music age would have been defined by files and folders instead of songs and albums," Mayer said. "Though the medium of music has changed, the iPod experience has kept the spirit of what it means to be a music lover alive."

It was a more eloquent endorsement than the one Mayer made at MacWorld, when he said of the iPod, "It's like the opposite of terrorism."

Armstrong backed Mayer's sentiment.

"I take my running shoes and my iPod with me everywhere," the seven-time Tour de France champion said. "I listen to music when I run. Having my music with me is really motivating."

Blige said it was hard to remember what she did before the iPod, calling the device "an extension of your personality and a great way to take your favorite music with you everywhere you go."