There are so many evil things to do and so little time. The easiest would be to send out an email virus on the global email listing which means every person who works there across the country would get it.

1. put security passwords of 20 numbers long on every file.
2. Make a letter firing boss from the owner.
3. call his wife and tell about the secretary.
4. Make a memo to give to accounting for me to get a big-check .
5. all of these be done with his signature except # 2

change all of the important phone numbers so no matter who they tried to call it would be the wrong number...

Lol... seeing as how I am an administrator... and nobody else there has full access to anything, I'd reset all theri passwords and lock them out of everything. Then I'd make sure every machine in the office had a paper jam becuase none of them know how to clear one, and I'd change all the voicemails to say they were no longer accepting new clients. THEN I'd pour a few cans of pop into the fish tank, unplug each and every chord from each and every computer and/or outlet, and take my but to the unemployment office first thing Monday morning.

Leave the moment they fired me. This actually happened to me about 20 years ago. The boss came up to me first thing Friday morning, and told me I was fired, but I could finish out the day. I immediately walked to the time clock and clocked out.

"What are you doing", he asked,"Didn't you just hear what I said?".
"I'm leaving", I replied,"You just fired me. I have no reason to be here any longer".

So, technically, I left early. Hey, what was he gonna do, fire me again? I already had another job lined up, and was about a week away from turning in my notice anyway.

take my company truck (its new) and run it into the mud, then let all the horses out of their stalls and turn all the cows loose and give everyone all the managers home phone numbers.

well the last job I was fired from,me and a friend took the tires of my bosses car,left them in place and towed it off