To Chat on Facebook Without Openng facebook.com

There are many sites which allow facebook chat without opening www.facebook.com. There are many reasons why people would want to use other sites. One reason is because facebook isn't opening, or the chat isn't working well on facebook.com. Another reason would be because the actual www.facebook.com would be blocked if your at school, college, work etc. This would be another way for accessing:-
 

1. www.meebo.com There are 2 advantages you can use Facebook chat even thought the actual Facebook site is blocked and secondly you can connect with your friends for other IMs
2. www.chitchat.com It provides a tab window so that a user can talk to many friends at once. It also show notification when friends come online and go.
3. http://adium.co.uk/ If your a mac user, adium is the best choice. It also supports multiple IM networks, like Windows Live Messenger, AOL Aim, Yahoo Messenger, Skype etc.