Annoyed with Facebook chat overtaking your browser windows?
This solution is simple: Link

iChat

1. Go to the iChat menu and select “Preferences.”
2. From the “Accounts” tab, click the “+” and select the following settings:
   • Account Type: Jabber
   • Account Name: your Facebook username@chat.facebook.com
   • Password: your Facebook password

3. Click down to server options and select the following settings:
   • Server: chat.facebook.com
   • Port: 5222
   • Uncheck “Use SSL”

enjoy.