Digsby is one of the newer ways to communicate with friends and colleagues across different protocols. It has been available to the world for around a year or so. Unlike the somewhat disappointing and overly long in alpha or in beta Trillian the builds or versions appear quickly and work pretty well.
Digsby requires a separate sign up to keep track of your different logins and accounts. Some privacy concerns are obvious here but are addressed as best as possible on a ‘Security Practices’ page. Over all a good product with responsive support and continuous development, at least at the