Napster isn't just a big app on campus any more. One of the fastest-growing software applications ever has made its way into nearly 900,000 office computers across the US, Media Metrix reported Monday. The at-work traffic numbers more than doubled the number of Napster users since May, when there were 417,000 PCs in the workplace using the file-swapping application. There were 4.9 million at-home Napster users in July, triple the number in January, Media Metrix reported. The battles in court between Napster and the Recording Industry Association of America (RIAA) likely played a role in the extraordinary growth, said Media Metrix senior vice president Bruce Ryon. Napster CEO Hank Barry put a positive spin on the news, which declared that Napster was the fastest-growing application ever measured by Media Metrix. "We're pleased that Napster has been acknowledged as the fastest growing application in Internet history," he wrote in a prepared statement. "These figures, coupled with the significant increase in CD sales during that same time period, demonstrate the tremendous opportunity that Napster offers for music lovers and artists alike." The Media Metrix findings could "feed into the growing concern about unproductive use of the Internet at work," said Eric Rolfe Greenberg, director of management studies for the American Management Association (AMA). The AMA, which represents about 10,000 companies, has found that most companies are trying to cut down on the non-work use of computers at work. Nearly half of all the corporations the AMA represents monitor employee Internet use, he said. While some companies even make allowances for recreational surfing, about 17 percent said they have fired someone for inappropriate Internet use. Napster could end up being a liability for corporate America, Greenberg argues, if the courts now hearing a lawsuit against the file-swapping site rule in favour of the record companies. "If Napster violates copyright law, and company equipment was used on company time, that could mean liability for the company," Greenberg said. Neither Napster nor the RIAA had any comment on the new findings. Media Metrix also reported Monday that 4.9 million home PCs visited Napster at least once in July, outpacing other more established applications including Real Jukebox and Microsoft PowerPoint. The report also tries to debunk the idea that Napster is just being used by college-age students sucking up a university's bandwidth. In fact, according to Media Metrix, 35 percent of all Napster users are between the ages of 35 and 54. Just 15 percent of all Napster users are between the ages of 18 and 24. For news, reviews, MP3 nuggets and more, see the new MP3 Newsroom. What do you think? Tell the Mailroom. And read what others have said.