I getting started with zend framework 2 and they have a prerequisite of an installation and configuration of mod_rewrite for apache. Apache 2.2.22 came pre-installed on Mac
If you are serving your site from ~/Sites, the trick for me was modifying my /private/etc/apache2/users/USERNAME.conf file. Initially, the content was:
Options Indexes MultiViews FollowSymLinks ExecCGI
AllowOverride None
Order allow,deny
Allow from all
Changing AllowOverride to all and then restarting the server with a quick sudo apachectl restart enabled me to start using mod_rewrite in .htaccess files living beneath ~/Sites.