you can also remove the banner in the bottom (advanced prefs) and the combobox box at the bottom too (loggin tabs of preferences)...
and for the interested, here's a screenshot of a "minimalistic" version of amsn that we did for a user (maybe 5 years ago) because he needed amsn to fit in less than 100 pixels :
http://kakaroto.homelinux.net/amsn_compact.pnghow do you like that ?

(note, it's not really possible anymore, at least not easily)