The Trillian version of Tomethicons was for Trillian 3.1. It has not been released for Trillian Astra yet. Don't worry, I haven't forgotten all of you loyal users. :) I will be maintaining Tomethicons for Trillian as long as I can. Above is the current preview of the base icons.
If you have Trillian Astra 4.2, you can download the
weekly build here. ( It should be updated automatically every Wednesday. The automatic updater is currently broken. Hopefully I can fix that soon.) Unzip the file to \stixe\icons or %appdata%\Trillian\stixe\icons. If everything is in the correct place, you should be able to select the icons under preferences->skins->Emoticons, Icons, and More.
What I'd actually like to do is release it as a JISP set (see Tomethicons (JISP)) then just create a JISP -> Trillian adapter package to allow Trillian to use any JISP files. That way I don't have to keep updating the 'pack for Trillian anymore and can just update the 'adapter'. (It may mean adding my own extensions to the JISP format for mobile, video, etc, but I'd rather do that than recreate the 'pack with every new version of Trillian.) That way I could do the same with NecronomIcons and Χ-maçons and have everything updated at once when things change. Alas, unfortunately, STIXE isn't built to be able to handle arbitrarily-sized icons everywhere, so I doubt this is going to happen.
(2010) NOTE: This iconpack is in a state of incompleteness right now. Things have changed since I last edited the code and there are a few places the code is out of sync with the icon graphics. Post on the discussion page if you find issues, so I know what I need to work on.