A Piece of Glass

I recently worked on a complete web site redesign project, converting the site from classic ASP to ASP.NET.  Many of the page URLs were going to change (despite the fact I kept the .html extension), so I whipped together a "redirection system" in the form of an HTTPModule.  The module simply checked that the file exists (or will be handled), and if not, queries a database to determine if the requested page has a "new" location.  It then sends a "301 Moved Permanently" response with the new URL (and logged the referrer so they can be notified of the new location, etc).  This system was meant for internal redirects only.  Of course, someone put an entry into the database redirecting an old page to an external page.