Social engineering is high-level con artistry; using smooth talking to compromise computers and networks, rather than hacking passwords or uncovering software exploits. It’s how Apple Tech Support let two kids get past all its security controls. And it is how, at Defcon, Wal-Mart’s network was exposed.
So while passwords and encryption are important, it is just as important not to give away information about your systems. The details of your computer, your software, and your network are nobody’s business but yours (and your IT person’s).
Update: Right on cue, from Lifehacker: How Can I Protect Against Social Engineering Hacks?