It's funny... I don't consider myself a web browser or a heavy email user, but with Viigo, Jive Talk, Pocket Day Pro, (weather), occasional gps use, OTA downloads, etc., I average about 40 mb per month.
True unlimited for $30-ish would rock. My monthly bill is about $130, give or take.
I understand the economics and harbour no ill will to Canadian carriers. Doesn't stop me from wishing for cheap data though.