How do you document your interaction flows?

For many years I've been using an evolved version of Jesse James Garrett's Visvocab diagramming style for documenting information architecture and interaction design concepts.

Today though we're doing a lot more in-page transformations in lieu of navigating to individual pages: things like accordion views, light-boxes, overlays, AJAX inclusions on demand, etc. JJG's Visvocab is coming up to being 10 years old, and thus wasn't designed to cater to all the new interaction modes we have today.

What diagramming style or notation do you use to map out your interaction flows?