Flourescent lights, especially the one above my head. This is a different one to the one I've moaned about before. It's extra bright and extra-evil and headachey and was on for all of five minutes which put me in a foul mood all day. Which then brings me on to the second thing to go to Mordor - people who spread stupid tales around the workplace, prompting you to write long and indignant e-mail messages and have meetings with your trade union rep, only to find that said tale was a big alarmist lie. That's exactly how an Orc would behave.