Ways to be obnoxious:

Insist on keeping your car windshield wipers running in all weather conditions
"to keep them tuned up."

Practice making fax and modem noises.

Finish all your sentences with the words "in accordance with prophesy."

Signal that a conversation is over by clamping your hands over your ears.

Yell random numbers while someone is counting.

Adjust the tint on your TV so that all the people are green, and insist to
others that you "like it that way."

Staple papers in the middle of the page.

Publicly investigate just how slowly you can make a croaking noise.

Honk and wave to strangers.

Try playing the William Tell Overture (The Lone Ranger Theme) by tapping on the
bottom of your chin.  When nearly done, announce, no, wait, I messed it up,"
and repeat.

Go to a poetry recital and ask why each poem doesn't rhyme.

Stand over someone's shoulder, mumbling, as they read.

Leave your turn signal on for fifty miles.

Sew anti-theft detector strips into people's backpacks, etc.

Sing the Batman theme incessantly.

Follow a few paces behind someone, spraying everything they touch with a can of
Lysol.

While in engaging conversation suddenly stare up at a fixed point overhead in
total confusion.

Specify that your drive-through order is "to go."

Leave someone's printer in compressed-italic-cyrillic-landscape mode.

Repeat everything someone says, as a question.

While making presentations, occasionally bob your head like a parakeet.

Lie obviously about trivial things such as the time of day.

Make beeping noises when a large person backs up.

Push all the flat Lego pieces together tightly.

At the Laundromat, use one dryer for each of your socks.

Drive half a block.

Lick the filling out of all the Oreos, and place the cookie parts back in the
tray.

Chew on pens that you've borrowed.

Invent nonsense computer jargon in conversations, and see if people play along
to avoid the appearance of ignorance.

Wear a LOT of cologne.

Cut your lawn with scissors.

Incessantly recite annoying phrases, such as "sticky wicket isn't cricket."

Stare at static on the TV and claim you can see a "magic picture".

Select the same song on the jukebox fifty times.

Do not add any inflection to the end of your sentences, producing awkward
silences with the impression that you'll be saying more any moment.

Never make eye contact.

Never break eye contact.

Construct your own pretend "tricorder", and "scan" people with it, announcing
the results.

Make appointments for the 31st of September.

Write the surprise ending to a novel on its first page.

While speaking to others, confidently misuse as many words as possible within a
short period of time.

While speaking to others, use a strange word repetitively as much as possible.

While engaged in conversation, no matter where you are, ask the other if they
mind if you slip off your shoes because you feel extremely overheated and
sweaty.

Sneeze or blow your nose directly in front of another and prior to shaking
hands.

In intervals, keep turning on and off your road hazard flashers while driving
along.

Make it habit to tell others continually that what they are wearing that day
"isn't their best color".

Keep asking the same female, every time you see her, if she's expecting.

When conversing with anyone seated, announce to them that the way they are
sitting is offensive to you.

Turn off the lights immediately upon entering someone's office, or, when
exiting someone's office.

While sitting at your desk, soak your fingers in Palmolive.

Insist that your e-mail address be zena_goddess_of_fire@companyname.com

Every time someone asks you to do something, ask if they want fries with that.

Highlight irrelevant information in scientific papers, then cc them to your
boss.