America now has her own National Jukebox! The Library of Congress has digitized thousands of 78s and made them available online, so you can get your fill of opera, blues, ragtime, bluegrass, yodeling, sermonizing, country and western, jazz, and so on. But be warned: the homepage features this disclaimer. "WARNING: Historical recordings may contain offensive language."
There is also a very cool slideshow of the archival preservation and digitizing process.
Hat tip to author Joe Bonomo for the link.