Apple has sold 174.1m iPods

"To put that number into perspective, enough iPods have been sold to provide a personal 'Pod to every man, woman, and child in the United Kingdom, Australia, the Netherlands, Greece, Israel, Sweden, Austria, Chile, Denmark, Ireland, Switzerland, New Zealand, and Greenland. And you'd still have enough leftover to give one to each fan attending Super Bowl XLIII eight days after the Mac turns 25."
Source: RegisterHardware, 18th November 2008, citing Apple figures