I recently upgraded my OS on my Macbook Pro to Leopard.  I must say it was as painless as possible but there are a few hiccups given I have a web server and a few other development-oriented programs running on my notebook.  Apache and PHP were not working and I have an issue with the Fire multi-chat IM client, plus some classpath issues in Eclipse IDE.

To get Apache and PHP working again:

- Preferences: Sharing: Web Sharing [turn on]

- Leopard installs PHP 5 and Apache 2.2 and I learned that it creates an entirely new config directory for apache.  I racked my brain over this one as it used to be /etc/httpd/ …  all the configs looked correct until I learned that Apache was now running from /etc/apache2/ so I edited the httpd.conf file and turned on the php5 module and restarted Apache and it worked.

- sudo vi httpd.conf  and uncomment the line w/ the PHP5 module

- sudo apachectl restart

I am still working on the Eclipse issue to get that working again and will likely use a different multi-chat client (unless Fire has an upgrade).