Apple Computer's iTunes music store now <A HREF="http://news.zdnet.com/2100-9595_22-5965314.html?tag=zdnn.alert">sells more music</A> than Tower Records or Borders, according to analyst firm the NPD Group. The research company tracks downloads from digital music stores, as well as people's purchasing habits at offline retail stores. During the past three months, iTunes made it to the U.S. Top 10 sales list for the first time, NPD said.