If you find that you need some other form, send out letters with that information. For example, sometimes mother's maiden name is used. I guess it is to a point. Hacking takes more advantage of holes in security while the social engineering takes advantage of holes in people's common sense. Finding your marks through a hole in the fingering system is a great way to start an engineer.
Many fingers give full names last logins, login locations and all sorts of info.
Find someone who hasn't been on in quite sometime. There are also the classic schemes. Pretending to be a sysop in an IRC or online chat room can make people give up passwords with ease. Yes, generally actions taken in the Internet or online are considered traditional hacking, but your knowledge of the average human's wetware comes into play. This is pretty damn important.