This ties into the other thread I posted about Privacy.

So in case you are scared to turn on chat for fear that your boss or the dreaded annoying friend will see you online, there is a VERY simple solution.

First make sure that you have the people that you don't want to chat with in a List (see other thread Part A up steps 1 through 3).

Now, once you have that done, when you go to click on Chat on your bottom right-hand corner you will notice that they are organized by lists. and right next to the name of the list there is a "switch" that you can make go from gray to green for that particular list. (turn chat on or off) To not be viewed as "offline" (not viewed in chat at all) to people on one of your lists, just turn the switch for that list to Gray ("Go offline").

They will not be able to see you on chat/chat with you.

But you will still be able to with your other friends.