November 2006 marks the fifth anniversary of one of the most successful products of the digital era, Apple Computer's iPod music player. Since 2001, potential iPod-killers have come and gone like autumn foliage. Apple claims an astonishing 76% market share in the U.S. for the iPod (60% of the UK market) and an equally amazing 88% share of the U.S. legal music download market for its companion iTunes online store. Over 60 million iPods and 1.5 billion songs have been sold.

Still, this autumn, the iPod could face its greatest challenge. Microsoft, after failing for years to combat the iconic gadget, will launch a new assault Nov. 14 with a player called Zune. Unlike past Microsoft music efforts, the Zune will be sold by Microsoft itself, and, like the iPod, it will be tightly integrated with companion software and an online music store.

Not only that, but this week, RealNetworks' Rhapsody music service, the best of the iTunes competitors, will announce its own player, jointly developed with SanDisk, which is the second-place player maker, albeit a distant second.

So, this holiday season Apple has made some of the biggest changes to the iPod and iTunes in years. It has redesigned the iPod Nano and Shuffle, cut prices and/or raised capacities on all models, introduced a new iPod search feature, added color games and movie playback to the full-sized iPod, and more. Plus, it has given the iTunes software its biggest overhaul ever, making the software both simpler and more fun to use.

Oh, and it has started selling downloadable feature films, which can be played on computers, iPods, and, soon, via a forthcoming new device, on TV sets.

For the main iPod, the biggest changes are in capacity, price, battery life and software. The base version, which holds 30 gigabytes, is now about £149, a £30 price cut presumably intended to put pressure on Microsoft. The higher-end model, at about the £229 mark, is also £30 less than last year's version, even though it holds 80 gigabytes, up from 60 gigabytes last year. Battery life for video playback has been greatly improved, to 3.5 hours on the base model, up from just two hours on last year's model. The bigger model has 6.5 hours of video playback time, up from 4 hours. (Battery life for music is unchanged.)

The iPod's screen is also now 60% brighter. But what's now on the screen is even more interesting: There's now a search feature that lets you find items alphabetically, by using the scroll wheel to select letters. In our tests, it worked well. And, in addition to viewing full-length movies on the full-sized iPod, you can now play classic color games, such as Tetris, Pac-Man, Bejeweled, Poker and Mahjong. Apple sells these games via iTunes.

The iPod Nano also has the new search feature, but it can't play the movies or games. It has been given a new aluminum skin, like the old iPod Mini had. This has two advantages: It resists the scratches that affected the first Nano models last year, and it allows for a range of bright colors. It's even a teeny bit thinner and lighter than the amazingly small original Nano.