You should hide apache banner information from being displayed so the attackers are not aware of what version of Apache version you are running and thus making it more difficult for them to exploit any system holes and thus making vulnerability scanners work harder and in some cases impossible without knowing banner information.
Example:
Apache/2.2.0 (Ubuntu) PHP/5.2.6-2ubuntu4.6 with Suhosin-Patch mod_perl/2.0.4 Perl/v5.10.0 Server at www.webaddress.com Port 80
How To:
Modify /etc/httpd/conf/httpd.conf
Change the ServerSignature line to: ServerSignature Off
Change the ServerTokens line to: ServerTokens Prod
Restart Apache: /sbin/service httpd restart
For ubuntu you will find these setting in /etc/apache2/conf.d/security
Restart Apache: service apache2 restart