Audio Archive : Free Audio : Download & Streaming : Internet Archive. 10 Big Myths about copyright explained. See EFF notes on fair use and links from it for a detailed answer, but bear the following in mind: The "fair use" exemption to (U.S.) copyright law was created to allow things such as commentary, parody, news reporting, research and education about copyrighted works without the permission of the author.
That's vital so that copyright law doesn't block your freedom to express your own works -- only the ability to appropriate other people's. Intent, and damage to the commercial value of the work are important considerations. Are you reproducing an article from the New York Times because you needed to in order to criticise the quality of the New York Times, or because you couldn't find time to write your own story, or didn't want your readers to have to register at the New York Times web site?
The first is probably fair use, the others probably aren't. Creative Commons Deed. Creative Commons.