If you are a regular Facebook Chat user, you will be happy to know that Facebook has recently launched the XMPP support which allows you to connect to FB Chat from (almost) any IM applications (only applies to those that support the XMPP protocol).
For Ubuntu Karmic users who are using Empathy rather than Pidgin, some of you might have difficulties connecting to the FB Chat network. The most common seen problem is the Authentication Failed message. Here’s the fix:
Open your Empathy. Go to Edit -> Accounts.
In the new window, click Add.
Select Jabber in the dropdown field and check the box “Reuse an existing account“. (Do not select “Create a new account”. You will have authentication error later on)
Enter your Facebook login name and append @chat.facebook.com at the back as the Login ID. For example: firstname.lastname@example.org
Enter your Facebook login password.
That’s it. You should be able to connect to Facebook Chat from Empathy now.
Note: If you have just created your Facebook username, you will need to log out and login again to your Facebook account before you can connect with Empathy.
For those who are connecting from other IM applications, you can easily add your Facebook chat with the following configuration:
Protocol: XMPP or Jabber
Username: your facebook username
Jabber ID: email@example.com
Password: your Facebook password
Use SSL/TLS: no
Allow Plaintext Authentication: no