My httpd.conf:
# The part that loads the modules.
LoadModule php4_module /sw/lib/apache2/modules/libphp4.so
LoadModule php6_module /sw/lib/apache2/modules/libphp6.so
LoadModule php5_module /sw/lib/apache2/modules/libphp5.so
# The part that does the virutal hosts.
<VirtualHost *:8080>
ScriptAlias /php6/ "//sw/usr/local/php6/"
Action php6-script /php6/bin/php
AddHandler php6-script .php
</VirtualHost>
<VirtualHost *:8081>
ScriptAlias /php5/ "/sw/usr/local/php523/"
Action php5-script /php5/bin/php
AddHandler php5-script .php
</VirtualHost>
<VirtualHost *:8082>
ScriptAlias /php4/ "/sw/usr/local/php447/"
Action php4-script /php4/bin/php
AddHandler php4-script .php
</VirtualHost>