Just the other day, a bunch of astronomers in the department were chatting. At first people were bitching about how little undergrads know (a typical conversation between profs, TAs, etc.). Even though it's a bit disrespectful, it really is unbelievable what some first year students don't know (ratios for example, or simple algebra), so I can understand the frustration.
However, the conversation then turned to include examples of things "everyone should know". One professor was absolutely disgusted that less than half their class thought it was possible for the Moon to be up during the day. Well, I'm going to admit this right now: I didn't know this until I was in my undergrad. I know plenty of PhDs that wouldn't know this now! You know why? Because the general public doesn't stare up at the sky every day, monitoring the positions of celestial objects! It's not that they're stupid, it's just that they're not totally engrossed in astronomy day-in, day-out. Once you tell them that's the case, most will understand and realize that yes, in fact, they have seen it in the day-time sky.
Another person said "If you asked a person on the street what one of Newton's laws are, they wouldn't be able to tell you!! I think that's so sad." Again, why would someone not in physics/astronomy know this off the top of their head? What's interesting is they probably know the laws, they just don't know them as Newton's laws. This does not make them stupid or ignorant!
What these people don't get is it's a two-way street. Someone from business could ask these people what process management is and be appalled when they couldn't answer. Or someone from geology could ask them to categorize a bunch of rocks, and the same thing would happen. It's all about what you do on a day to day basis, and to be self-centered enough to think your work should be known and understand by everyone on the planet is just plain naive.
The most annoying case of academic snobbery is when people complain about the accuracy of science in movies. This has come up recently with the movie, 2012. I don't know about you, but I don't go to movies to learn about science!! I go there for the entertainment, to get away from science and real life, and to have a good time. If all movies were scientifically, historically, politically, etc., etc. accurate, we'd just be watching documentaries all the time. Don't get me wrong, I love me some documentaries, but I like to go into a fantasy world too.
So, to all you academic snobs out there - get your heads out of your asses, lighten up a bit, and have some fun already!