A friend is...someone who genuinely likes you and sticks around even when the "bad weather" sets in? I don't know really, it sounds like an easy question, but it's actually much harder to answer. Especially as the line between friend and associate, or "someone you recognise" is easily blurred these days - facebook certainly manages to prove that.
Personally I have 2 best friends, one who I met in High School and was similarly picked on as myself, and the other who I've known since I was 5 years old in reception class. It was much simpler back then, because when we were in our infant years we made friends with anyone who was nice and allowed us to play with them, without SA being an issue. Growing up we were all considered the "freaks" of the bunch, so we had a lot of common ground in that sense and luckily enough we had similar interests as well. Although I still have communication troubles, fears of inadequacy and of losing them, I'm also well aware of how lucky I've been in comparison to some other SAers out there, friendship-wise. I don't see either of them much anymore - we mostly restrict visits to our birthdays and present exchanges at Christmas, but we're still in touch at least. The rest of the time I don't really hang with anyone, sticking to mostly solitary activities like a lot of others here.