[frankosaurus]

+1

Sequence diagrams force you to think about the flow of control in a system.

When reviewing draft designs, I sometimes ask the author to convert a simple boxes-and-lines architecture diagram to a sequence diagram. It can be revealing.

[jongjong]

I can relate. It's an essential communication tool. When discussing asynchronous events with a colleague, there is a point in the discussion when it becomes almost impossible to explain it in words and you really need something like a sequence diagram to communicate accurately.