A year ago I mentioned Wavago as an IM aggregator, along the lines of Adium or Trillian. I tried it, but didn't like the interface so kept Trillian. I just got an email that suggests Wavago has been purchased by a product called Raketu, that will automatically import your Wavago clients, but that also supports dialout to landlines and mobile phones. Might be worth a look. I'll try to get to it next week.
Update: Wavago contacted me to make sure there was no confusion - "Wavago is simply shutting down. Raketu did not purchase Wavago nor is Raketu Wavago. Raketu simply bridges to Wavago as it does with the other protocols."