If you're running OS X Panther (10.3) and want to get LiveJournal up and running, here are some helpful hints:
1. use the mod_perl that's already installed. You just need to uncomment mod_perl from the /etc/httpd/httpd.conf file.
2. There's a great mysql 4 package that installs everything you need at mysql.org -- there isn't one for mysql 3.x.
3. installing DBD::mysql is a problem on panther unless you do this:
Edit /System/Library/Perl/5.8.1/darwin-thread-multi-2level/Config.pm, replacing:
ld='env MACOSX_DEPLOYMENT_TARGET=10.3 cc'
With these three things, the installation went much smoother for me. Hope that helps others too.