Guy Kawasaki: Don't Write a Mission Statement, Write a Mantra!
Applicable to every and any kind organisation: your guiding philosophy that will be felt by all those who have a stake in it, as well as the prospectives who are looking to engage it.
DISCLAIMER:
I blog on MS Word - and I frequently backlog because I don't have the time to write everything on the same day, so please ignore the TIME of post.