4 by 2.4 by 0.8 inches
From CNET's review: Our favorite part of the design by far is the scrollwheel used to navigate the menus. When holding the device in one hand, it's possible to move through every song, album, or playlist in mere seconds. Unlike other jog dials or button navigation systems, the scrollwheel accelerates as you turn it, allowing for the kind of maneuvering that's necessary to rapidly peruse 5GB worth of MP3s.
4.0 by 2.4 by 0.72 inches
Looking back: I kind of liked the mechanical scrollwheel of the first generation. Still, the Synaptics-aided touch wheel was a technological marvel, and 20GB of storage for only $499--what a deal! Also, Windows users started to buy these things en masse and pair them with Musicmatch, helping Apple gain a solid hold on the MP3 player market. --CNET's James Kim
4.1 by 2.4 by 0.62 inches
From CNET's review: Between the display and the scrollwheel are four buttons: rewind, menu (which also moves you up one level during navigation), play/pause/power, and fast-forward, all of which are reachable with your thumb when you're holding the device. You can turn off their orange backlighting (along with the display backlighting) to save power or set it to turn on when you touch a button. All six front-panel controls are incredibly touch sensitive; they almost seem to respond to heat rather than pressure. Luckily, the hold switch prevents accidental activation.
3.6 by 2.0 by 0.5 inches
From CNET's review: Although it scarcely seems possible, we think the Apple iPod Mini's design surpasses even that of its photogenic older sibling. Its stylish, anodized-aluminum shell is so tough that we felt as if we could stand on the device without consequence. Apple constructs the body by hollowing out Mini-shaped aluminum tubes so that there are no seams in the construction, then applies the color during the anodizing process so that it can't scratch off.
4.1 by 2.4 by 0.57 inches; 5.6 ounces (20GB)
From CNET's review: The newest iPod is slightly thinner than its predecessor, measuring 4.1 by 2.4 by 0.57 inches and weighing 5.6 ounces. But the most noticeable new attribute is the Click Wheel, which adorns the megapopular iPod Mini. Gone are the four buttons located just beneath the display, which--as most users of the last iPod would agree--were hard to identify, inconsistent to the touch, and often difficult to access with one hand. Instead, they are now ingeniously integrated into the touch-sensitive wheel and reminiscent of the original user-friendly iPod.
4.1 by 2.4 by 0.63 inches; 5.9 ounces (30GB)
4.1 by 2.4 by 0.75 inches; 6.4 ounces (40GB)
Looking back: This one is still my favorite of all time. A color screen, decent battery life, the perfect size and weight, and a big Click Wheel--to me, this one makes a better audio player than the fifth-generation version, though the original pricing ($499 for the 40GB version) was far out of reach for many shoppers. --James Kim
The iPod U2 (20GB only) shares most of its characteristics with the fourth-generation iPod but boasts a few key differences. The most noticeable is the player's black body and Ferrari-red scrollwheel--it definitely pops. Flip over the device, and you'll find another distinguishing design tweak: the signatures of all four U2 band members have been laser-etched in the iPod's shiny, silver rear casing, which also features a U2 stamp and the words "special edition."
The iPod Shuffle (1GB, 512MB) was both commended and ridiculed when it debuted as Apple's first flash-based player. The stylishly minimal MP3-playing USB stick was designed to be worn, and it made a nice second unit for iPodders. Alas, the nice-sounding player had no extra features, not even an LCD. This iPod popularized the concept of randomly shuffling your music, though most MP3 players before it already had this feature. Read the review.
This was a classic: better battery life, a spiffed up ClickWheel and a maximum capacity of 6GB. Read the review.
This is the photo version of the red-and-black U2 edition.
From CNET's review: Just when you thought Apple's standard iPod was overly saturating the public consciousness, Steve Jobs and company pull another beauty from the company's bushel. The Apple iPod Nano sets new standards for gadget design and stretches the boundaries of technology. It's the world's first 4GB flash player, yet it's also one of the thinnest. Plus, it boasts a bright color screen that takes advantage of the bigger iPod's photo capabilities, though be aware that the Nano's screen scratches easily.
From CNET's review: Experienced iPod users may complain that essentials such as a power adapter and A/V cables aren't bundled with the device. But despite the fact that it is an audio player first and foremost--and that the term is overused--all of you will remember the fifth-generation iPod as the video iPod.
Originally debuting with fourth-generation technology (a monochrome screen with a cCick Wheel), then later with a color screen, this special-edition iPod, a collaboration between Irish rock band U2 and Apple, is basically a red-and-black version of the fifth-generation iPod. Read the review.
The iPod gains many incremental improvements, including a brighter screen and better video battery life, but probably the most appealing aspect is the tantalizing price points of $249 for the 30GB version and $349 for the huge 80GB version (available in both white and black). Read CNET's full review.
The second-generation Apple iPod Nano is like the successful offspring of an iPod Mini and a first-generation iPod Nano. It's small, stylish, user-friendly, and competitively priced--a great player all around and suitable for a variety of users. Read CNET's review.
1.62 by 1.07 by 0.41 inches
From CNET's preview: You might as well call the second-generation Apple iPod Shuffle "the iPod Microscopic." Still screenless, the silver anodized-aluminium iPod Shuffle is, according to Steve Jobs, the smallest MP3 player in the world. While we can't confirm this claim just yet, we can say that this wearable player continues the Shuffle tradition of blind control while listening to music. While we aren't huge fans of a screenless MP3 player, this model will definitely appeal to those who like their players small, cheap (1GB, $79), and easy to use.
This special red 4GB Nano will sell for $199, with $10 of every sale going to the Global Fund, which helps women and children affected by HIV and AIDS in Africa.