Apple iPod (2001)

 If the Walkman is the aging king of portable media players, Apple's iPod is prince regent. It rules the realm of digital music like no other device: According to the NPD Group, more than eight out of ten portable players sold at retail by mid-2005 were iPods. Yet when the $399 iPod first appeared in October 2001, it was nothing special. It featured a 5GB hard drive and a mechanical scroll wheel, but worked only with Macs. A second model released the following July offered a 20GB hard drive, a pressure-sensitive touch wheel, and a Windows-compatible version. But the third-generation player, which appeared in April 2003, proved the charm: A 40GB drive, built-in compatibility with Windows and Mac, support for USB connections, and a host of other small improvements made it wildly popular, despite its relatively high price and poor battery life. Now the fifth-generation iPod threatens to do the same thing for a new breed of portable video players.