Applying a skin to Trillian is easy, but for some reason there’s not a lot of documentation out there on how to install sound packs. It took me a while to figure it out: you have to copy the sound pack folder into
/Program Files/Trillian/stixe/plugins, then open up Trillian Preferences > Skins, click on “Advanced,” and select the sound pack from the “Sounds” dropdown menu.
I mention this because I found an iChat skin for Trillian Pro. I use the free Trillian Basic, and being something of a default-mode lover (more on that some other time), I’m okay with the standard Trillian skin — but I wanted a gentler sound scheme. While the iChat skin is only for Pro users, it does come with an iChat sound pack which can be installed into Trillian Basic just fine, using the directions above. It’s so nice to have light and gentle “whoosh” sounds accompanying my messages now, rather than the urgently shrill notes of the default Whistler theme.