I just found this one - all those interested probably know about it already, but for the record..
http://martybugs.net/software/iiUsage/download.cgi
iiUsage will display a graph and detailed breakdown of your iinet bandwidth usage & it's tray icon tells you at a quick glance where you're at.
Bad pun ahead warning.. sorry.. has to be written...
Now I can keep an ii on my usage.