The nerdiest feature of all time... simple SVN logs.
Here's the RST code:
.. svnlog:: https://ra-blog.googlecode.com/svn/trunk/
And here is what it does:
You can see the entries are nicely formatted. That's because this restructured text directive connects to your SVN server, retrieves the changelog, parses it, tries to process the individual entries as restructured text, and then formats and spits it out again.
I decided to add the recursive parsing because I tend to format everything I write as valid restructured text anyway. But that means I can include images, tables, files, and even other logs in my entries.
How is it useful? Well, I intend to have my projects' pages written using this. This way I don't need to keep a changelog.
Also, I bet the title is right ;-)