DISQUS

I would do a bit more research.
"It integrates your MySpace (not Facebook …. boo!) IM account"

There is, indeed, a plugin, made by outside, for Trillian for facebook. A google search will yield it, or you could try the Trillian plugin list on the CS web-site. Might even work with Trillian Pro (so, all Trillites could use it this very minute!).