iPod shuffle (2nd generation)

Apple shrank the shuffle into an aluminum square with a clip on the back and stopped pretending it was a stick of gum. It weighed 15 grams. You clipped it to a collar or a waistband and forgot about it, which is a different relationship with a device than any other iPod offered. 1GB, $79, and five anodized colors that Apple rotated every year. Still no screen. The control ring stayed, the USB plug moved to a dock because the body was too small to hold a plug, and battery life ran 12 hours. It is the smallest thing Apple has ever sold with a battery in it, and for running it was better than anything that came after.