Apache performance tuning - Expires Headers

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
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