When Facebook first added its chat feature, many people turned it off by default.  It has never worked well.  It’s buggy, you can’t save your chats, you can’t chat with more than one person…the list goes on.

One thing it seems to excel at, however, is ensuring that the one “friend” on your friend list that you’d rather not chat with will be guaranteed to strike up a conversation at the least opportune moment.

Well, they’ve made some minor improvements to the chat recently, the most useful of which is that you can now “go online” for a particular group of friends.   Let’s say you create two “Friend Lists”…one for co-workers and one for peeps (and yes, you can put people in multiple groups).  When you get home from work, you might not want to be bugged by your co-workers, so you can “go offline” for that Friend List, but “go online” for your peeps.

Block Facebook Friends From Seeing I’m Online in Chat | LA Snark.