SEO Freelancer as well any other Web Developer sooner or later draws visual sitemap just to show to his/her client future basement of a new web site - web site structure.
More often than not we have simple structure, which consists of 'about', 'news', 'contact' pages. Simple sitemap is enough and we could choose any piece of paper, software approach, but sometimes it is better to turn on Adobe Photoshop or Illustrator to show all aspects of future building in structural view.
Did you hear of Mind Maps from NLP or brainstorming?
Mind Map Tools in most cases are great tools to represent idea, make decision, and architecture of future project. These tools are perfect for collaboration, brainstorming and can be used for business processes modeling, idea polishing, as well almost any life task. But with Web 2.0 in one hand and Mind Maps in another we can develop web interfaces, realize hidden possibilities of design - generate beautiful responsive sites. Try, for example, mindmeister. You can drink coffee and skype to your far client about details of web site structure at the same time. Isn't it a beautiful world?
For a simple sitemap you can try WriteMaps - a free web-based tool that allows you to create, edit, and share sitemaps online.
Another elegant online sitemap visualizer is Slickplan.