I've told my family about my SA, but haven't begun telling friends about it yet. I'm not sure why, though; I'm pretty sure people think I'm messed up to begin with, so I don't think there's that much to lose in telling them about my SA. Like grumblina said, many people perceive me as snobby or aloof or sometimes even hostile. I have a bad habit of staring... if someone looks at me I'll stare em into the ground lol. It's not agression, really; well not all of it. I'd say it's equal parts shock (like "omg! why are you looking at me? what have I done now?") and defence. But the wild eyes sure put the wind up people. I know for a fact I give people the impression I don't like them.
I'd tell friends about my SA, but I don't really have "friends", as such -- just acquaintances. I know a LOT of people and I get by in light conversation, but I never feel close to anybody; I feel that my relationships with people (even intimate relationships) are superficial and meaningless. If I were to tell somebody about my SA, I'd have to trust them. And at the moment, there's noone even close to qualifying...