Block IM on Facebook?

I know Instant Messages are a popular feature of Facebook, but I’d like to use FB without letting anybody know I’m online. 90% of the time I get IMs, they are from very chatty, pesky people I knew from high school whom I don’t have the heart to de-friend outright, but I would rather deal with in something other than real time, like e-mail or wall posts. (Part of this is the 13-hour time difference between Korea and the US East coast; their lunch break is when I’m trying to check my messages before I go to sleep.)

Is there a way to disable this feature? I can’t find it under “Privacy Settings.”

Open up the chat window and click Options. Then choose “Go Offline”.

Also, when the Option panel loads, the names of all your friends lists will load (if you haven’t made any lists, it’ll just load “Friends”). To the right of the list names will be a circle on a green background. Push the circle to the right and the background will turn gray. This makes you offline to Friends. If you have more friend lists, you can choose which ones to appear offline to.