I did manage to get Omeka running on my Mac. OS X 10.5.5 has Apache automatically installed and running but PHP is not enabled nor is it configured correctly for mod_rewrite. In addition, Apple has its own location for most of the configuration files. If Apache is not running use System Preferences / Sharing and click the checkbox next to Web Sharing.
Here are the steps I followed:
1. Modify Apache httpd.conf
Open a terminal:
sudo vi httpd.conf
(Of course you can use any text editor you like. I just use vi because it's handy.)
Find and uncomment (delete the # at the beginning) the line loading PHP.
#LoadModule php5_module libexec/apache2/libphp5.so
LoadModule php5_module libexec/apache2/libphp5.so
Find and change the "None" to "All" for the line
Save the file.
Restart Apache2 with:
sudo apachectl restart
2. Setup Omeka
On Macs with OS X 10.5.5 the default directory for Apache2 is `/Library/WebServer/Documents'.
Install the Omeka unzipped files here. I created a directory for the name of my project and put the Omeka files in that directory.
3. Install MySQL on the Mac.
Get the install from http://dev.mysql.com/downloads/mysql/5.0.html
4. Setup Omeka account in MySQL
Just as the install instructions for Omeka suggests. Don't forget to modify db.ini file to point to the Omeka database you just created.
5. Find mysql.sock
mysql.sock is not in the same place as on a Linux server so we need to create a link for it. First make the directory where Omeka expects to find mysql.sock.
sudo mkdir /var/mysql
This is where Omeka expects to find mysql.sock. But on Macs mysql.sock is in /private/tmp/mysql.sock. So I just created a link:
sudo ln -s /private/tmp/mysql.sock /var/mysql/mysql.sock
6. Install Imagemagick
Follow the instructions at http://www.imagemagick.org/script/binary-releases.php
You should now be able to go to http://localhost/omeka_directory_for_your_site and start to create your site.