You need to install c and python headers to be able to compile PIL:
sudo apt-get install build-essentials python2.4
And also libjpeg and zlib for PIL
sudo apt-get install libjpeg62-dev zlib1g-dev libfreetype6-dev
--
No plone-site in dropdown menu in the ZMI
Plone needs PIL installed and there is no python-imaging package version
in Ubuntu Jaunty for python2.4, that's the reason not to have Plone
Site in the ZMI. How to detect it:
1. Stop zope instance (through the ZMI - Control Panel - Shutdown)
2. Start the zope instance in the foreground: