As far as I know Trillian only has a webcam feature for Yahoo, but even then only if the other person (the "broadcaster") doesn't use the latest version, otherwise you'll only get a black screen. That's because the new Yahoo messenger uses JPG2000 compression instead of what they used before, and Trillian still hasn't released an upgrade to fix that problem (again AFAIK).
I'm not sure, but you might be able to use Logitech's webcam software with Trillian too (read
http://www.bigblueball.com/forums/to...p?TOPIC_ID=980 )