I used Omnigraffle to create these rather verbose IA diagrams with the purpose of exploring and tightening up the IA of a web application by removing unneeded barriers and make the experience faster and make navigating through the site much more intuitive.  

 

The IA methodology is based off of Jesse James Garrett's "A Visual Vocabulary for Describing Information Architecture and Interaction Design" [http://www.jjg.net/ia/visvocab/]. This method was supplimented with ideas presented by Richard Cecil over at UXMatters [http://bit.ly/15NUqYE] in order to better illustrate asychronous interactions.

 

If you'd also notice, some of the elements have version numbers.  Those are used to better locate the wireframes that correspond with those element types or pages.  It was a suggestion first presented to me via Scot Przybylski [@scotprzybylski] on Dribbble.  Its pretty handy, I must admit.