I whistle tunelessly to myself when there’s no music playing; I lipsync when there is music. I do not have conscious control of either of these activities.
I chew my nails noisily and spit out the little nailbits.
I groan loudly when my code fails to compile.
I got fired.
I hired both of my managers and then got laid off by my, how shall I say, less user friendly bosses. They got stuck with the morons that I had insulted them from. It’s still driving them crazy.
I amuse myself by bringing the network up and down to see who’s paying attention.
I torment them with the remote-control fart machine (hidden in a new place daily! Active RF transmitter range of 50 feet! Wait until they’re on the phone with SO/headhunter and let fly!)
I hide behind corners and snipe at them with my Nerf arsenal.
I offer them change randomly for no good reason. Apparently, this drives one woman round the twist. I save it up for her. 
Yes, it’s good being the assistant IT manager. I’m like the Diet Coke of evil.
We got this “Managing Anger in the Workplace” brochure a while ago. One of the tagline quotes on the back of it is “In the past decade, the number of individuals who kill their supervisors has doubled.” I cut this out of the brochure and stuck it prominently on my cubicle wall so that it’s one of the first things that you see if you come over.
Well, I eat pizza for lunch most days when many of them are still trying to be faithful to Weight Watchers.
I also never take responsibility for my week to recycle, because I stopped working on Fridays and I forget to check on Thursday to see if I’m signed up for that week…
And I never, ever catch the phone when the receptionist is away from her desk.
Is this stuff we do on purpose or just can’t help it?
Cause I’m such a nice person, I don’t TRY to annoy my coworkers. (Wish I could say the same for them!)
I would never say this in my current position because I have a very conscientious bunch of co-workers now, but in my past work environments, my answer would be “My job, and damn well, might I add.” 
I make more money than most of them! Thats the reward for 15 years of dedication in the face of cost cutting apathy. They can hire 3 people at minimum for what they pay me… and believe me I keep reminding them of it!
Also apparently I have an “active and interesting sex life” that appears to be the subject of many conversations…
I don’t try to be annoying. I was just about to go off on a rant about my office-mate’s annoying habits, but then I thought, well, he’s probably got no clue how irritating he is, so I began wonder how annoying I am, and I started paying attention and realize that it’s a miracle he hasn’t tied me up with his mouse cord and beaten me to death with his keyboard yet.
I read the SDMB and snort.
Then I don’t (or CAN’T) tell them what I was laughing at.
Drives 'em up a wall.
I whistle endlessly. Also, one time I used the word “boyfriend” in a sentence, which really set this one guy off, let me tell you. shivers He’s not working there anymore. eg
Whenever anyone comes over to ask me a question about something I did a month ago, a week ago, yesterday or this morning, I claim that I don’t remember. Mainly because they’re too lazy to look up what was done in the computer but, strangely enough, not too lazy to walk all the way over to my desk to ask me. They’re hoping I’ll just do whatever needs to be done now for them.
I talk to myself. Well, not really. I talk to inamimate objects. I lecture the computer when it misbehaves. If I’m on hold and the standard recording comes on, “Your time is valuable to us. Really, we think you’re peachy keen. Please continue to hold for 20 more minutes while we patronize you by telling you how much we care”, I loudly hiss, “Shut up! Shut up!” If I’m trying to use an automated touchtone system and it decides to get uppity, I have been known to say, “Don’t tell me you’re effing sorry. That IS the correct account number. Zero zero zero zero (while repeatedly hitting the zero key). Don’t give me your attitude, bitch!” Today I had the pleasure of speaking to an exceptionally idiotic customer service rep. When I hung up I shrieked, “Incompotence!” in a very high-pitched theatrical voice. My co-workers always do the same thing - look at me from the sides of their eyes and hunch down in their chairs in fear.
I really don’t remember.