Mash Up: Yes, Twitter updates are limited to 140 characters but using phrases such as "kthnxbai" (the new "talk to the hand") makes you look like you've leant on the keyboard with your elbow. It's almost as annoying as using "Tw" as a prefix to create a twitter related activity. There's a knack to articulating yourself in 140 characters - this is not it.
Funny Girl: More of a female trait (in fact, I can't think of a single guy that does it), the habit of writing "lol" after every tweet does not make me think you are funny. This practice gravitates over to Facebook too and I see it a lot in groups where the demographic is quite a bit younger than me. Or maybe I just have higher standards.
Sealed With A Kiss: Another female idiosyncrasy, although I have seen a few men starting to do it now, but does every tweet have to be signed off with a kiss? x
Trendsetter: Does writing the same hashtag 10 times over in one tweet really help to get it trending? And another bugbear of mine is someone asking, "Why is xxx trending?" It's probably because people keep asking "Why is xxx trending?"
Crowded House: Yes, Twitter is a great place to jump into conversations but it can create the situation where there are too many names in the twitter conversation to add any actual conversation.
Spamalot: Because of the amount I tweet I must be a spammers dream and use obvious keywords. Recently I don't seem able tweet anything without bot accounts picking it up and offering me the link of a lifetime. Block. Report. Move on. But what is the point? Do people still fall for these amazing offers? Are these the same people who give out their bank details to people from Nigeria?
Attack of the Clones: It annoys me so it must annoy you. Promotional tweets from multi-twitter accounts and linked Facebook accounts? They fill my (and your) timeline with repeat information which is beneficial to no-one.
Written in the stars: I don't believe in horoscopes and I don't look up my own. What make me think I want to read your horoscope, especially one that is truncated so I have to click a link to see the rest? Have a quick look in your Twitter -- Settings -- Applications and see what shite you're allowing in your Twitter stream.
Blog posts telling you how to tweet: 'Nuff said *wink*