Hello there! I'm Miranda Rensch, Product Manager at SEOmoz and lover of visual communication. Communicating visually is one of the most effective ways to explain complex concepts and relationships, and can be a great way to explain your services/products and create valuable site content. I often use diagrams and whiteboarding in order to communicate new features and concepts internally with my team.
I've compiled a list of tools you can use to create visualizations, or simply use to communicate visually with your teammates. Enjoy, and feel free to add your own suggestions in the comments!