Opera Sites

The Metropolitan Opera: http://www.metopera.org/home.html; The 2002-2003 season includes performances of Mozart's Don Giovanni (K. 527) and Die Entführung aus dem Serail (K. 384).
New York City Opera On-Line: http://www.nycopera.com/; This nicely done site includes, besides the standard schedule and ticket information, biographies of composers, including one of Mozart, and many opera synopses. The 1997-98 season includes performances of Die Zauberflöte (K. 620).
OperaGlass Mozart Page: http://rick.stanford.edu/opera/Mozart/main.html; A comprehensive (and very ambitious) opera site. It includes a complete list of Mozart's operas, detailed information and librettos for selected operas and links to the rest of the OperaGlass site. Highly recommended.
The Opera Schedule Server: http://www.fsz.bme.hu/opera/main.html; Search this database to find out where Mozart's operas are playing around the world. (Or those of any other composer, for that matter.) Very cool site.
Stuart Burrows: The Official Web Site: http://www.geocities.com/Vienna/8685/; The official Web page for tenor Stuart Burrows, who has sung many roles in Mozart's operas throughout the world. Includes a brief biography, a discography and RealAudio sound files of some of his performances.