With sales down more than $5 billion since 2000, the record business desperately needs to generate some cash. One of the most radical ideas is picking up steam: Why not have Internet service providers charge customers five to ten dollars a month — and let them file-share to their hearts' content? With an estimated 538 million people using the Internet worldwide, according to Nielsen Online, this cash infusion could float record labels for a long time. "ISPs, telcos and tech companies have enjoyed a bonanza . . . off the back of recorded-music content," U2's manager, Paul McGuinness, said to a roomful of artist managers at an industry conference in January. "It is time for them to share that with artists and content owners."