Interaction Matrix
Bill Scott of Yahoo! posted a short article about how he uses an "Interaction Matrix" to document rich interactions. I really like this approach because of how it explicitly details out each actor and state within the interaction.
In the past, I have used more of a storyboard approach, which essentially mixes actors and states into a single diagram. But sometimes I worry that details get overlooked within a given storyboard frame. The approach that Bill is proposing would relieve that anxiety, while still creating an easy to use document. Maybe creating a single storyboard to go on top of the matrix would then show it in an easier to read fashion for stakeholders.
Bill has posted 2 templates to work from for Drag and Drop as well as Inline Editing. Check out the article: Interaction Matrix
