PyBlosxom has a flexible callback mechanism that allows pretty fine grained mamipulation of your entries as they are being rendered unto HTML or RSS or whatever you want your output to be. That's real useful since the templating engine, while fast, does not allow any calculated values. This is no Cheetah. Luckily defining callbacks to calculate specific values is simple.
One of the finer points of publishing on the web is that titles matter. Putting the name of my site, the date, and the title of the article all in the html title of a page is what I currently do in Bulu and something I want to duplicate as I migrate to PyBlosxom.
This is just a matter of creating a plugin that hooks the cb_prepare callback. This callback is activated right before rendering takes place. The implementation is simple, it checks if the page about to be rendered has only a single entry. If it does then is sets the value of data['single_entry_title']. Through the magic of the templating system the value of that will be avaiable through $single_entry_title in a template. In the case that there is more than one entry than $single_entry_title will evaluate to an empty string.
The source code is placed under the Python license.