Soundboards have become an Internet tradition. Typically they consist of dialog snippets from movies and television and serve as an aid in making prank phone calls (as in using Arnold Schwarzenegger's voice from Kindergarten Cop to ask "Who is your Daddy and what does he do?" and other such questions from the film).  Now Octrock over at 4 Color Rebellion has put together a soundboard of music and sound effects from Super Mario Bros.  Just point and click the various icons to recreate your own Mushroom Kingdom audio experience (available in downloadable Windows format or online Shockwave format).  It's a fun little time waster, and while it won't help much for prank calls, it will stimulate the nostalgia center of your brain.  I bet you can tap out the sound sequence of World 1-1 without even really thinking about it.  I know I could.