This online service promises to help you reduce costs with less time and fuel travelling by scheduling your route in the best way possible, and increase income by freeing up more time to service clients.
Currently US only, but I emailed them and they say they will have Australian maps in VERY shortly - weeks away.

http://www.aceroute.com

It's free, and no software to install. they have add-ons that you do pay for.

Worth a good look