"The Japanese company that makes the Rio line of MP3 players is shuttering its portable digital-audio division. Rio parent D&M Holdings said on Friday that the ultra-competitive business no longer fit its market strategy. Although it has only a small market share compared to Apple Computer's iPod, the Rio brand name has been linked with the early days of digital-music history since weathering a lawsuit from the recording industry that aimed to shut down the MP3 hardware business. D&M Holdings--which also owns high-end home audio brands including Denon and Marantz, and is close to acquiring Boston Acoustics--said the portable MP3 player business required too much investment, and didn't offer enough return, to warrant continuing."It's a sad day when the pioneer of an industry bites the bullet. Rio made some of the first MP3 players that laid the groundwork for the digital audio players that we have today, but evidently they just weren't able to stay competitive. Too bad, because Apple needs more competition!