I would normally go with the no fear approach.
I tend to talk about it the same way I would talk about being a woman, it's a non-issue, it's nothing bad or shameful, it just is - like if someone was to make a sexist comment if they were to make a negative comment about asperger's I'd pull them up for it, it's their problem not yours. Depending on the situation I may cut-out that person.
With that said however...
I have on my info that I'm aspie, but I have yet to really discuss it on updates, I keep making updates talking about my frustration with unemployment, today it was about how useless my disability adviser is, and an old friend from high school asked me what my disability was, in a concerned sweet kind of way. I deleted the update rather than tell her, it's not out of shame for what I am, but that it is a non-issue and I would worry about people thinking differently about me. When I knew this friend I was far worse than I am now, the label of asperger's would just explain that, it's not like I've suddenly picked-up some sort of illness, and most people I know will know there's something a little 'odd' about me so would understand my being aspie.
I babble - I think you just have to not so much announce it but just mention it when it comes up, like it's no big deal, because really it's not. If people ask about it answer their questions, if they make jokes then respond accordingly, a comment of 'we always thought you were a little odd' is okay but say if people refer to you as a ret*d or 'assburger' I'd say ditch them.
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Bloodheart
Good-looking girls break hearts, and goodhearted girls mend them.