Recordings of appellate arguments in the United States Supreme Court and 10 federal circuit courts are now available from a website and twitter feed. With updates every 15 minutes, the sites let you play, search, and download the recordings.
Kudos to Brad Heath, a journalist with USA Today, who developed the sites.
Praises also to the National Center for State Courts. It similarly complied a site that has links to oral argument recordings from several state appellate courts.