We we released our older version of our shipping extension through Brookins Consulting. Graham added significant documentation and cleaned up the code. You can find it in the projects area, BC_Static_shipping. http://projects.ez.no/bcstaticshipping
This is a good example to follow. We will be releasing our real time shipping extension which grabs current UPS and USPS shipping rates in the near future. You can see it in action by going to http://Alconeco.com The static shipping was the base for our real time extension developed by Ez Partner Xrowe.
Additionally you may want to look at this extension http://projects.ez.no/recurringorders
