Click the (+) Add Contact button at the top of the contact list.
Right-click in your contact list and choose Add..
While in a conversation, click (+) Add Contact
A dialog box will appear. Choose the group that the contact should be placed in. If a new group is needed, click "Create New Group". Then choose the contact's chat medium. (NOTE: AIM and ICQ use the same option. For either AIM or ICQ contact information, choose "AIM&ICQ". On the next screen, enter EITHER a screen name or ICQ#.) The next screen will ask for the contact information. (NOTE: For Y!, there is a box to send the contact a notification message.) For all mediums, click the "Add Buddy" button or the contact will not be added.