Hi folks,
i made this business directory for lawyers, attorneys and law firms.
I use 2 level taxonomy and location module.
For display i use Views, Views Hacks (for hierarchical display of Practice Areas, which are taxonomy terms) and Panels (only for attorney content type and front page)
Here is my website developed by me only, with the help of Drupal 6, because 7 is too new to me and I just love 6 Drupal 7 because I've manage to learn a lot about 7 and I now like it very much.
Back in 2009 we built this site using Mediawiki. In 2010 we ported it to Drupal 6, and just today I finished upgrading the site to Drupal 7. Drive the Americas is a wiki in that anyone can edit and contribute information. We have a very active user base and average around 150-200 unique visitors every day.