Just in case you weren't up on Apple Computer's dominance in the digital audio market, In-Stat last week announced that Apple now owns over 30 percent of that market, thanks to strong sales of iPod devices. The market for both hard disk-based and flash RAM-based portable digital audio players will top 104 million units by 2009, the company says, up from 27.8 million units in 2004. Digital audio player revenues hit $4.5 billion last year, up almost 200 percent from the previous year