When you are feeling so sick that you can't make it to work, you __________ sick.

Yesterday Bill and I got to talking about quitting jobs and how people have done it. One woman said she got her boss on the phone and said, "I'm calling in quit." (Instead of sick) This silly argument between Bill and me has been there from the start and will never end. Bill says the phrase is most commonly 'call in sick.' I say the phrase is most commonly 'call out sick.' He says if "Bob called in sick today," it's about the direction in which the call is going. But if Bob is the one who called, isn't that redundant? Don't we already know the call was incoming and not outgoing? I say if "Bob called out sick today," it was Bob letting his work know he would be 'out' due to illness.

How do you say it?