I have AS, just to be clear, and I don't care who knows. I'm open about it. I'm hanging out with a new friend on Friday and up and told her that I have AS (and what it is, since she didn't know). In turn, she told me a related secret about herself. One friend said, "Well, that explains a lot!" when I told him (he'd never understood why I don't hug people when everyone else we know does, for example). Another friend apologised profusely for using "autistic" in a mocking way in my presense and swore never to do it again, whether or not I was around. Most people either asked questions about it, or were just like, "Oh, yeah, okay." Another of my friends has alcohol-induced schizophrenia -- she's very open about it, which encouraged me to be open about AS. They don't treat me any differently than they ever did.
However, I would NEVER mention it on a job interview out here in the Midwest. While I think it would make little difference on the East or West Coast, I think here it would put me right out of the running. To me, AS is a personal thing -- my choice who I tell and who I don't. However, I'm not the least bit ashamed of it, so I see no problem telling my friends or anyone who flat-out asks. (Only had one employer do so, and all she said was "I wish you had told me that earlier!")