Tom Chi, has a new article at OK/Cancel about the needs and challenges of having a detailed functional spec. He throws open the floor for folks to comment on what works for them. As a long time reader of OK/Cancel, I can tell you that they will get a bunch of great responses – they have a very insightful audience, and foster a great collaborative environment. Check in on this thread regularly – it will only get better.
In fact, you should tag it at del.icio.us, to help even more people find it. Of course that wouldn’t hurt for Tyner Blain either :)