OSX Leopard and PATH issue

[Tony Crockford]

Background:

I have a PHP script that uses exec() to run ImageMagick to make jpg  
thumbnails from PDF's (needs ghostscript too)

it worked more or less out of the box on Tiger - I installed Mac Ports  
from the .pkg installer and IIRC that was it.

on Leopard (using the native install of Apache) I have added /opt/ 
local/bin to my $PATH and while ImageMagick works fine like that it  
couldn't find Ghostscript until I edited IM's delegate.xml file to  
include the full path to gs

I suppose my question is, does anyone know why that might be, and how  
I could tell Apache to use my $PATH variable?

TIA