Nat Pryce shares lessons learned with FIT
* Know your Audience
* Nobody in the Team "Owns" the Specifications
* Intersperse Explanatory Text
* Reuse Fixtures Between Many Specifications
* Refactor Fixture Classes Very Aggressively
* Refactor the Specifications
* Don't Drive Business Objects Directly
Nat's lessons echo my own, especially, "Know your audience". Personally, I've found FitNesse helpful in making it easier to "Refactor the Specifications".
These short bullets don't do the article justice, I recommend reading it for yourself.