It was only when Joel Ross posted this blog entry on the subject that I became aware that IIS6 includes the ability to compress files to enable speedier transmission.  Armed with this exciting new knowledge, and some additional information from Scott Forsyth, today I set up compression for files of type aspx on the dev version of a web application on which I'm currently working.  It took just a few minutes and resulted in an 80% reduction in bytes transmitted.  This is a great feature, and yet not one that seems to be particularly well-known.  A decent GUI would probably help matters, avoiding all that unnerving spelunking in the metabase.  But still, cracking results for just a few minutes' effort.