I was searching around the Trillian site for some compact skins and found a good one called Microscopic. What sets it apart is that while it’s very small, you can also set the options so you can view avatar icons. That’s good. Also, there’s a little customization utility which will make setting up the skin easier. While I was looking around, I also found nikebball87’s skins. I remember Dervish from years back when I was using that skin on ICQ. Currently, I’m using his port of the Geek skin.
One thing that’s interesting is that both Microscopic and Geek both have alternate contact list modes (Trillian Bar as it’s known apparently). I had no idea this existed and had to do a search. You can switch to it on the skins that support it via Preferences, in the Contact List panel at the bottom. I’m not sure how useful it is (although w/ it rolled up, you can keep it on top of everything), but it sure is nifty.