So I've been on the Trillian Astra (multi-service instant messenger program) beta for some time now. I totally love it and can't wait for it to go to production so I can pay these guys for their great work.
I just discovered a nifty feature today by accident and wanted to share. Typically, I use the custom hotkeys to show and hide the contact list, then double click the contact I want to IM with.
You can, however, drag individual names or entire groups out of the contact list and drop it, and it will create an always-on-top mini list. I tend to only IM about three people most of the time, so it fits quite nicely hovering in the corner!
Way to go Trillian!