The apache distribution that ships with OS X PB has dso support built in. To see for yourself, open a terminal and type the following command.
If you've compiled your own version and didn't have it use the name "apache" the below should work for you.
I was able to get things working by doing the following after running the .pkg install. Hope this helps.
1. Add the following lines to /Library/WebServer/Configuration/apache.conf
LoadModule php4_module /System/Library/Apache/Modules/libphp4.so
If some of you have hosed your apache install I'd reccomend re-compiling from the darwin apache source which is already reconfigured/patched to compile on Darwin/Mac OS X PB. That source can be accessed from:
Personally, I use...