Assuming that your friends, co-workers, and family members aren't all experts in 3D technologies, you probably blew their minds when you showed them your new HTC EVO 3D. Some variation of "Whoa!" presumably came out of their mouths first, likely followed by "How'd they do that?"
That kind of question is usually rhetorical, as most people don't want a technical explanation of something they're only asking about because of what you just showed them. But since your fancy new phone has already made them think a little more highly of your technologically savvy self, it doesn't hurt to give your pals an actual answer (provided that you're not impersonating Nick Burns when you do it, of course).
Better yet, show them the handy graphic below instead. It's faster than having to repeat "parallax barrier."
If you can say "parallax barrier" without being interrupted by "para-what?" then go ahead and say that the EVO 3D has a parallax barrier screen overlay, which is why the 3D is "glasses free" and the viewing angle is so narrow.[OnlineSchools.org]