User Interface stencils

Free
UML 2

UML 2

Additional UML diagram tools, esp. for Use Case and Activity diagrams. There is also a Domain object for class domain or namespace groupings in Class and Collaboration diagrams.

Free
Web Flowchart

Web Flowchart

Charles Parcell has created a very slick set of stencils for website flowcharting that has just about every component you might use for a site, from Flash to PHP to .Net. And all of them in a unique, colored style. Awesome.

Free
Flow Map Shapes

Flow Map Shapes

We make flow maps daily to visually represent how users move through a system. We find that maps which depict screens and the results of user actions from those screens are easier for our clients to understand than the long text-heavy documents usually produced during the definition phase of most large web site projects. Most...more

Free
Mind Mapping

Mind Mapping

Use this stencil to represent words, ideas, and tasks arranged around a central idea.