Whoa there! What I just tried to download was 12.1 megs! One of the reasons I want to watch my usage is because I'm running up against the limitations of my account.
I get my internet access through a wireless pcmcia card and some custom software supplied with it. Unfortunately there is no networking icon displayed in the taskbar so I rely on the sometimes flakey custom software to track my I/O.
But none-the-less, that's for your suggestion.