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IMessenger is a Facebook application that works in a similar manner as Meebo, offering an ajax instant messenger service thata doesn't require a login, and operates directly from your profile page. Any Facebook friends that add the IMessenger application to their own profiles will automatically show up on your buddy list. Friends can also be added manually, and you can initiate a conversation with another user if they are logged in. Similar Facebook apps include Meebo and Saki.
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