When would it be a good idea for you to sign a
• Presenting an invention or business idea to a potential partner, investor, or distributor
• Sharing financial, marketing, and other information with a prospective buyer of your business
• Showing a new product or technology to a potential buyer or licensee
• Receiving services from a company or individual who may have admittance to some sensitive information in providing those services
•Allowing employees access to confidential and restrictive information of your business over the span of their job
Having said this, in case you're uncovering a trade secret, which you should do in the rarest of occasions, the obligation to keep up the secret should be an absolute must. This is because once an obligation to keep up the information confidential is gone, then it no longer can be deemed a trade secret. Courts won't protect your right in that trade secret after you've consented to it being publically revealed.