The company that introduced the world to personal music players more than 20 years ago with its Walkman line of cassette players, hasn’t exactly been leading the pack when it comes to digital players. Sony’s first attempt was considered a major league blunder, mainly because the players could only handle Sony’s proprietary digital rights management system. What good is an MP3 player if it can’t play MP3s?

But the company recently announced a new player, the Sony NW-HD5, which several publications have already referred to as a possible “iPod killer.”

What’s to like about the NW-HD5? Size is one thing. The unit is smaller than previous Sony digital players, plus the company has dumped the rectangular design of its previous models in favor of a more square, iPod-like shape. The player stores music on a 20GB hard drive and plays MP3s,WAV files and WMA files as well as Sony’s own ATRAC3 files.

But the best feature about the new Sony NW-HD5 is the battery. Unlike the iPod, which has had its share of battery woes, the battery for the new Sony digital player is removable.

That’s right! When the battery runs down you can just slide in a replacement and keep on rocking. As all iPod users know, when an iPod’s battery eventually refuses to recharge, you either have to take a chance with a third-party external battery or send the unit back to Apple for a replacement.

Sony says that its NW-HD5 can go for up to 40 hours playing the lowest-fidelity files; however, it’s more likely to last up to 30 hours playing your standard, 128 kbps MP3 files on a single charge. That’s almost three times longer than the iPod.

The Sony NW-HD5 will debut in Japan later this month. While Sony hasn’t officially announced a world-wide roll-out, the company did hint that it would announce international marketing plans for the unit shortly after its Japan premier.

Suggested retail price is $329.