If you want to to a quick test, create a very basic Joomla 1.5 template and then put this somewhere in the index.php file:
The name of this site is <?php echo $mainframe->getCfg('sitename');?><br />
The administrator email is <?php echo $mainframe->getCfg('mailfrom');?><br />
This template is in the <?php echo $this->template?> directory<br />
The URL is <?php echo JURI::base();;?>
This shows you the various new cals that can be made in 1.5.
A couple of people asked, so I have created a tiny installable debugging template for 1.5. This will install a template that has only 2 files, the index.php
and templateDetails.xml. I removed references to other files to give a bare
bones output with no CSS. This is actually a useful diagnostic template, you
can install it and track errors that are occurring with a component or module.