Apple has sold its 100 millionth iPod and is far outpacing its closest competitors, which have failed to make even a dent in the portable music player’s popularity.

Since its introduction in November 2001, the iPod has spawned an ecosystem of accessories that include cases, earphones, home stereos, and hardware for playing the device in the car. In addition, it has driven the success of Apple’s online music store iTunes, which sells more music over the Web than any other store.

In announcing its achievement Monday, Apple trotted out praise from Grammy Award-winning artists Mary J. Blige and John Mayer. The company even offered a quote from bicyclist Lance Armstrong, the seven-time Tour de France champion who apparently can’t be separated from his iPod. “I take my running shoes and my iPod with me everywhere,” he said.

Since the iPod’s introduction 5-1/2 years ago, Apple has unveiled more than 10 models. The iTunes music store’s library has grown to more than 5 million songs, and Apple claims to have sold more than 2.5 billion tracks.