One nice org-mode feature is "Babel", the ability to embed snippets of code in documents, run them during export and insert the results (either values or stdout) into other parts of the document http://orgmode.org/worg/org-contrib/babel/

Since my blog is mostly about programming, this lets me write the code I'm talking about directly into the prose (using C-c ' to switch to the relevant Emacs mode for editing that language) and ensures that the code and results match up exactly (including graphs generated with GNUplot).