I really haven't been vegetarian all that long so I don't know what people think yet(they ask, but no one has been defensive or whatever yet), other than I might be a little crazy. :-p My bf though, he worries a little how it comes across (not that I lecture, just my refusal of food). He hasn't told his family that we're back together yet (not something I'm looking forward to because his mom really dislikes me and I'm not too find of her either). The veg thing will be new to them. When I asked him if we'll see any problems in the future with that (me refusing food his mom cooked) he said, "Oh you'll have to eat it!" Uh, the hell I will! I told him that wasn't an option and she would get over it, I just wanted to gauge the situation before I went into it.
I think people DO view vegetarians as snobby or holier than thou, NOT because they are, but because that's just how they perceive them simply for being "picky" about what they eat. If you go to a b-day party and refuse the cake, it can seem snobby, like "oh I'm too good for their cake". Of course, we all know that's NOT the case.
I do have a back-up though...I enlist the help of my medical issues if simply being upfront about my vegetarianism doesn't keep people off my back. I state that meat and dairy didn't/don't agree with me and if that still doesn't work, I start to go into extreme detail until they decide that it wasn't worth acting like a moron over. LOL