You say you want to be creepy. One can not do such a thing on a lark. Creepiness is a lifestyle, a culmination of many small actions that originate in the creepiest part of your heart (the pulmonary valve).
At the movies, show up a little late. Slowly make your way to a seat in the middle of a crowded row, your butt facing the screen. Make deliberate, meaningful eye contact with every person you sidle past. Once you're seated, lean forward. Elbows rest on knees. Palms on temples. Stare at the patch of floor between your feet and adopt a pained expression. Hold for two hours.
Every time something vaguely humorous happens in the film, laugh just a little too loudly for a little too long.
The comic book store. Waste some time flipping through bins of Groo backissues until a girl enters the shop by herself. Wander nearby and stay within range of her, pretending to casually shop. Comment on the books you browse through in an attempt to pique her curiosity.
Wait until she picks up a comic, then approach. Ask if the book is for her boyfriend. Be confident that if she has no boyfriend, you are now by default a valid love interest.
Next, the shower. That's right, you still need to be creepy when you're alone. This isn't performance art - this is something that's done even when people aren't paying attention. Well, you know what I mean.
So, the shower. What you're going to want to do is apply your soap and shampoo as robotically as possible. Be rigid and hesitant, like you're mimicking poorly recalled human behavior. Realize that the water is too hot long after it has scalded your skin. To dry, stand perfectly still on your bathroom rug, silently weeping.
Fixate on the water circling the drain while applying soap to your abdomen. Keep lathering the same spot for several minutes while your gaze remains transfixed.
In a waiting room, always lean against the wall with your arms crossed, even when there are available seats. At some point, the receptionist will ask if you have a reservation. Cheerfully reply that no, you're good.
Bring at least a dozen copies of the same issue of Boy's Life magazine. Very slowly, add them one at a time to the collection on the coffee table.
On the internet, spot a video or article that allows for user comments at the bottom of the page, and submit one.
Leave a comment on every porn video you watch. Attempt to flirt with the starlet as though she posted the video and is actually keeping tabs on StreamBoobs or YouTug for insightful messages. Leave your email address so she can get directions to your house without the prying eyes of those other perverts.
In the crowd at the crime scene, pick a detective and watch them with hooded eyes. Smile slightly when he or she looks your way.
Find some way to stand out in the crowd of onlookers. If it's sunny, hold an umbrella. If it's freezing, wear an undershirt. If everyone else is a child, wear your college graduation cap and gown.
Wait until you've unsettled the detective. Slip away the very moment that a bus or truck passes between the two of you.
When you're in a public bathroom, commandeer a stall and proceed to cough. A lot. Deep, impossibly emphatic coughs. Punctuate the passing of every minute with an angry-sounding clearing of your throat.
With someone in an adjacent stall, whistle a peppy tune.
"Really, Holmes!" I dropped into my seat, shocked. "You are remarkably tall! What are you, six foot six? Six foot eight?"
As the 19th century diver approaches a giant clam, a flash of brilliant golden light flares from within the shell. I emerge in a swirl of bubbles and do the timeless universal underwater hand signals for the following: ZODIAC KILLER, KKK, BLOOD OF YOUTH
The Something Awful front page news tackles anything both off and on the Internet. Mostly "on" though, as we're all incredible nerds.