Well check out the team at Courier Quotes for a wordpress shipping calculator

This is perfect for stores run on wp ecommerce the get shopped plugin. The functions include quotes on multi courier , bookings and shipping labels best of all its free so get on the roll out list to get a free shipping calculator for your wordpress shopping cart. 

They started with wp - ecommerce because of the popularity. We think WP e-Commerce is an awesome WordPress plugin to work with for Australian customer. The team at Get shopped have made it highly extensible and they follow the WordPress theory of feature as a plugin first, core second. Because of that, the feature set for WP e-Commerce is almost limitless.

Now you can hook up your wordpress site to heaps of Australian couriers meaning no more cutting and pasting ! Wow too easy.