I've been known to say random things without really thinking - I'm trying to develop the surreal sense of humor I so want. Sometimes when I say something really nonsensical people around me will just say "Whoa." Sometimes they say that if I let on something not intended as humorous, such as suggestions of my true sexual orientation or political ideology .
Hygiene is an issue - my hair is longer now and over the course of a day tends to end up all over the place, possibly lending to my creepy image and making me seem less approachable. Plus, sometimes I feel like my deodorant isn't working (especially after gym).
Also, when I feel uncomfortable or depressed I sometimes mumble to myself and rock back and forth. Recently I've decided to acknowledge my creepy appearance and mannerisms upfront, such as by discussing it on social networking sites that I and my school chums visit. I get the impression that people are probably talking about me behind my back, especially considering the things I hear them say about other "creeps" whom I know.
I have done stalker-ish things before. I'd periodically look up my crushes' pages on MySpace or Facebook trying to get up the nerve to contact one of them. I don't know if they realize that, but that's got to count toward my "sketch factor" to some degree.
Also, I've creeped people out on the internet before. Like I once met someone on this site and we started talking for a few days. Then one night we were talking really late and I let my guard down, talking about my depressive moods and self-injurious habits. Then they suggested that we form a "long-distance relationship" to support each other - I was reluctant at first, but before long I was the one with the most emotional investment in it! I think they began to realize just what the hell was going on in the following days, because a day or two later (at a more reasonable hour of the day ) they suggested we were going too fast and gave the "we can still be friends" routine before I never heard from them again. In the months afterward I came to realize what a mistake it was to let my guard down and become too vulnerable and needy (but at least I got to make the mistake with some anon. on the internet before I had the police called on me in real life ).
This post was longer than I intended it to be.