There are a lot of tutorials out there how to setup local websites with virtual hosts on a Mac OS computer. Yesterday I tried very hard and it failed to work for me. I used a subdirectory of my Documents folder as virtual host document root, and that was my problem: the apache webserver process, running as _www, has no rights to access this folder. So either use some other path or make the Documents folder accessable via “chmod 755″.
Hope that helps someone out there 