Here's a quick tip to optimise the HTTP response headers sent by your webserver. While being pretty useless to the average user, the Server signature and powered-by headers could be removed or at least reduced. Obviously these changes are only minor, but on a heavily loaded server such as large forums, could make a decent little saving.
These two little changes...
apache2.conf
ServerTokens Prod
php.ini
expose_php = Off
Will change the HTTP response headers on this server from:
Server: Apache/2.0.54 (Debian GNU/Linux) PHP/4.3.10-16 \ mod_ssl/2.0.54 OpenSSL/0.9.7e mod_perl/1.999.21 Perl/v5.8.4 X-Powered-By: PHP/4.3.10-16
To:
Server: Apache
That's a saving of 128 bytes. This site has served 2025 requests so far this month, so this little trick might only have saved me 253kB, but what if there had been 20,000,000 requests?