Plone 3 global defines and tools
If you're in a page template and want to access something a little more complicated without writing a view class, try looking in this egg:
plone.app.layout[version].egg/plone/app/layout/globals/configure.zcml
It lists the global browser classes accessible from any page template (such as @@plone_portal_state)
and points you to the classes where everything is defined.
Some very useful stuff in there (for instance @@plone_tools)