This is a “warm blanket” agreement with which, by requesting your agreement to it, I am helping myself sleep at night by placing a small amount of formality on the sharing of The Idea. I believe The Idea will only improve as a result of having solicited your honest and clear feedback.
Rands shares a great idea for sharing great ideas – the FriendDA While this is a natural inclination amongst good friends, sometimes it’s nice to stress the importance of confidentiality of the information. Often times the conversation starts off with “don’t tell anyone about this, but I have this idea…” The FriendDA provides a shorthand for referencing a quick agreement of confidentiality among friends without getting too formal and it serves as a nice reminder that the idea’s originator trusts you and your opinion but wants to keep it quiet for now.
You don’t need to sign it, you reference it when you start the discussion, preferably with a pint in hand.