The newest iPod is about the size of a pack of gum, weighs less than an ounce, is solid state and can double as a USB 2.0 drive. It's $99 for the 512mb version, $149 for 1 gig. It's called the Shuffle because there's no screen - the theory is that everyone listens to their music in shuffle mode anyway, so who needs a screen.
The Apple Store three blocks from the Expo started the day with 2,000. They were sold out by noon.