People who just won't get to the point when they want to ask you something. It's especially bad when they call you up and do it, interrupting whatever you were in the middle of.
"Hey. How you doing"?
"About alright. Kind of in the middle of watching a movie. What's up"?
"Nothing much. Listen. I need to ask you a favor".
"Okay".
"It's gonna be kinda complicated, and you don't have to do it if you don't want to, but it's really important, and I need it, and I know how you are about your stuff, so I'm kind of afraid to ask about this, but things are getting kinda bad, and I don't know anyone else to ask who can help me out with my situation, so I figured I'd try and see what you'd say, and..."
"GODDAMNIT! WHAT"?
"...can I borrow your weedeater"?
...why can't they just flat out say "hey, can I borrow your weedeater"? And they never do it over anything big. It's always something simple, which somehow makes it worse. If you're gonna make that big of a production out of asking a favor, it better be worth the 15 minutes I have to spend listening to you circle around the whole point of the conversation.
Also this...
When someone phones you and you phone back about 3 seconds later and they don't answer.
It's even worse when they leave a voice mail stating "I need to get ahold of you IMMEDIATELY. This is IMPORTANT", and then they don't answer the phone for 3 hours, despite the fact they only JUST missed their call.
Really, I think anyone doing anything with a cellphone that extends beyond texting me gets on my nerves these days.