The repetitive behavior criteria tend to distinguish AS from simple social anxiety--that is, the repetitive physical movement (for example, rocking, hand-flapping, finger or foot-tapping, etc.), as well as having very, very strong hobbies that pretty much take over your life, and/or are very unusual (for example, being fascinated with blenders, or spending ten hours a day playing Tetris). Transitioning issues are also common--that is, being very badly thrown off by unexpected events; or being unable to switch from one thing to another. Children with AS may, for example, have a tantrum because someone is throwing a surprise party for them, or cry when they are told that math period is ending and they've got to go to lunch, because switching tasks is so difficult for them.

Oh, incidentally: I'm autistic, of some sort or another, depending on the psychologist observing. My own research says that my case either barely fits classic autism, or else drops into PDD-NOS territory (the uncharted diagnostic wasteland where most cases, under current criteria, are dumped); but I've also been diagnosed with Asperger's because I fit the "verbal" stereotype (I can speak well, though very formally).