User Interface stencils
Block diagrams are simpler process diagrams that are used to depict online processes. One diagram represents one process, for instance, registration. Block diagrams can be used to very quickly define how a certain task or process is completed online. The diagram depicts each step in the process with all the pages and...more
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.
User interface elements for the Windows operating system, in case you have to design an interface where Aqua widgets are considered a strange and mysterious concept, and licking them is totally out of the question.