I use Trillian 2.0 Pro on my computer (I can't buy 3.1 until later...)
I have used AdiumX and I have decided:
Trillian = Adium X
in terms of overall features but Trillians price tag ($25 for IMing software) makes AdiumX much better.
AdiumX offers most of Trillians features for free and looks a million times better.
I wish they would port it to Windows.
YOU NEED ADIUM X