One of the simplest things but yet most annoying is what people select to be their screen name on Instant Messengers.
ICQ is great simply because I have the ability to rename people on my contact list to what ever helps me identify them the fastest.
MSN on the other hand is terrible and way TOO many people change their name daily from quote to quote. That extra time I spend every day trying to figure out who each contact is because the names are different from yesterday is driving me nuts. MSN really needs to add a feature where I can control the names on my end because I'm not interested in peoples cleaver little quotes or the type of mood they may be in. I'm perfectly content with their real or handle name.