I was at a work party in a pub last night, and one of the barmen did something that annoys me: he was pouring someone else's order, while asking me what I want at the same time. So he's not paying attention to the pint he's pouring, and while I tell him my order then, I have to repeat it when he's actually ready to pour it. So taking my order when he wasn't ready to pour it was totally pointless. It annoys me when people try to multitask for no good reason: multitasking is overrated.