Ask HN: Resources on social engineering
Social engineering is of obvious interest to startups. Whether it's to get that contact with the CEO of a potential partner, or to get through to the sales manager who can give you a discount on your hosting plan, or even just to get past a gatekeeper and turn that lead into a sale, being able to work your way through the social network at another company is extremely useful.
What are some great resources (books, blogs, movies, or others) that you've found, on or off the web, that taught you to be a better social engineer?