Wasted me an hour figuring permissions etc, eventually found this: Thx. http://knowledgeisunlimited.blogspot.hk/2011/12/setting-up-cakephp-on-mac-os-x.html change your user.conf file in etc/apache2/….
<virtualhost *:80>
    DocumentRoot /Users/yourusername/Sites/pathttocake/app/webroot
    ServerName pathtocake
    <Directory "/Users/yourusername/Sites/pathtocake">
    Options Indexes FollowSymLinks
    AllowOverride All
    </Directory>
</virtualhost>

By michael