We need to give the users the option to serve gzip compressed content if the browser supports it.An article
on how the gzip compression works (how to make the webserver do it).An article
on how to gzip compress your content from PHP (that means not having Apache (the web server) do it for you). ...and one more
Reference to the apache_get_modules
PHP function to discover if the Apache server has the mod_deflate active.
Sample htaccess conditional directive for gzip'ing content from this article