When I lived in the US I was a ridiculously generous tipper. I worked as waitress at one point and all the wait staff I knew used to tip like lunatics because you knew what a great thing it was to get a great tip.
I've never tipped in Australia though apparently it's done sporadically in higher end places. People I know who wait tables in a hotel earn 17.00 an hour so though it would be nice to get a tip it's not exactly built into the wage.