[gmku]

Unreturned e-mails. Especially from people I know well, or are supposed to correspond with me regularly for official business. I myself have a 24-hour rule, where I return all e-mails within 24 hours, even if it's just to say, hey, got your note, can't answer yet but I'll get back to you.

I'm not talking about casual social e-mails or spam, but stuff regarding work or important personal business. It drives me nuts when editors I work for, for example, won't answer a simple inquiry about the detail of an assignment I'm working on, or an interview subject won't get back for days to set up an appointment.

I know many people don't work on their computers as much as I do during the day, and I know they're not just hanging around waiting for my messages. At the same time, in this day and age when electronic communication is so big a part of the business I'm in, it floors me when people don't respond in a reasonably timely manner.