We have also written how to add Facebook Chat in Firefox, and you may use iChat on Mac to send messages to your Facebook friends instead of signing in to Facebook web page. Here we are writing the method to let you know that how you can integrate your Facebook vanity URL with iChat.
Integrate Facebook Chat with iChat on Mac
Click on Finder
Navigate to Applications >> iChat
Now from iChat menu click on Preferences
Click Accounts icon and then click on ‘+’ sign to add new account
Enter following information: Select Account Type as Jabber, Account Name: email@example.com where user name is your’s facebook vanity user name and password and enter 5222 in Port text box and click Done
Now sign in to iChat and start sending messages to your Facebook friends