With the advent of YSlow, we should all now be aware of adding expires headers to our web servers. For my purposes, I wanted to enable it globally, then fine-tune per Virtual Host. In my Apache httpd.conf, I added the following directives: <ifmodule mod_expires.c> <filesmatch \".(jpg|gif|png|css|js|swf|ico)$\"> ExpiresActive on ExpiresDefault \"access plus 1 year\" </filesmatch> </ifmodule> [...]