What are you doing with Windows Workflow Foundation?

Next quarter, my team (MSDNEvents.com) will be doing a session on Windows Workflow Foundation.  As we were reviewing the content Today, some questions came up as to some of the scenerios where WWF would be used.

We did a lot of brainstorming and we came up with a bunch of ideas, but I thought I'd put the question to you... how are you using Windows Workflow Foundation?  Or, for that matter, more basic, how are you using workflow technologies in general?  Are you using Biztalk?  Some competitive technologies?  If so, what for and how?

We'll use some of the most interesting ideas for anecdotical evidence in our live presentations if it's ok with you.

Cheers,

Bill