These new iPod nanos are a riot of colour, even when the colour is charcoal grey. They are the coolest iPods yet.

There are nine, ranging from silver through to charcoal, purple, blue, green, yellow-gold and orange to red and fuchsia. There are two models, one with 8GB of solid-state memory ($249) and the other with 16GB ($329), a doubling of previous storage at roughly the same prices.

It is slimmer and lighter (38grams) but slightly longer than the previous “tall” nano and the click wheel is slightly larger. The slightly curved screen is now glass.

The case resumes the slim vertical format of the first (plastic case) and second (alloy case) nanos. The 32×240-pixel screen is sharp, brilliant and looks huge, although it is the same five-centimetre diagonal as the previous nano; just tipped up vertically.

An important addition is the accelerometer introduced in the first iPod touch. If you tilt the nano the screen changes from portrait to landscape, as on the iPhone and touch.

Shake it and the accelerometer will shuffle your music. Cover Flow, from ITunes, operates to scroll album art, just like on a Mac or an iPhone.

The accelerometer is also used in Maze, one of the three games on the nano. You tilt the iPod to run a ball through a maze – addictive but likely to drive you insane.

Purists suggest that the big lift for nanos occurred with the previous short, squat third-gen model; a Classic in miniature.

But for my money, this latest nano, sleekly curved and cunningly designed, returning to the slim verticality of the second generation, is the best yet in terms of design, software and electronic “sex appeal”. Battery life is better; there are more features for less money.

Except for the touch (because I bought an iPhone) I have owned a representative dozen or so of the 37models and generations of iPods to appear since the first scroll-wheel model arrived in October 2001.

I still have four: a black Classic (used with a Belkin TuneTalk stereo microphone for interviews), a “postage stamp” red shuffle, a red second-generation nano (also used with the Belkin mike) and now a fourth-generation charcoal-grey nano.

The offspring has designs on the “old” red nano and it will be difficult to resist her. “You have only two ears,” she said, thus demonstrating the keen observation and impressive logic present in the young. “You cannot possibly need three, let alone four.”

Ah, but these are desirable objects and, as any collector will tell you, function is not nearly as important as ownership.

So what of the desirability? Partly it is the design. They are beautiful in form and function. Their simplicity hides complex and clever technology. But there are also significant innovations.

The preview panel moved to the bottom of the screen where it is easier to read; it is smaller but you get more depth for track titles and other information.

In Settings you can increase the font size and shut off the preview to get more screen room. General and playback menus have been redesigned to improve readability.

You also get “Genius”, the software introduced with iTunes8 (a must-do download, free from the Apple website). You create a playlist on your Mac (or PC if you are still using one) and Genius recommends other music you might like.

The process is ongoing and new recommendations appear daily in your iTunes account for synching to the nano.

Finally, and one of this nano’s most interesting features: Spoken Menus, which uses the text-to-speech software from OSX to read the iPod’s menus out loud.

This helps if you have difficulty seeing the screen, as in bright daylight, or you could navigate music menus while driving (although safer not to, in my opinion). It also works with the metadata for track names, albums, and so on and it will speak information such as “low battery”.

The voice memo function is still there but the choice of “high” or “low” quality is gone. Recordings are now made in Apple lossless format, which uses much less memory than the previous WAV format.

This is a highly desirable new iPod and I love how it looks and works but I’m not handing any on. I like them all too much. grab your own free ipod nano