See When Others are Available and Chat Anywhere
Microsoft Office Communicator allows you to see when people are in meetings and when
they will be free. It also allows you to set your own
presence to Available, Busy, Away, and even Do Not Disturb for when you don't want
to be interrupted.
Tobegin a conversation, double click on the person you'd like to talk to and begin
typing. Hit enter when finished typing and immediately
they will be able to respond and have a real time conversation online.
Even if a person is not in your contact list, you can search for them. To do this, enter the last name of the person in the search bar at the top. It will display everyone with that last name. You can then start a chat by double clicking on their name, or right click and at the bottom there is a add to contacts. This will add the contact to your list.
To view someone's presence information, click on the arrow to the left of their name and it will show you the next time they are in a meeting or available.