First off, Love Opencart, and happy to be using it and contributing to it.

I ended up writing a shipping mod to suit my business's needs.
What we needed was a shipping module that calculated shipping by sub total.
So, in this mod, the shipping is assigned according to how much money the customer spent in the store.
You assign minimum values to a shipping cost in the mod.
Image of admin section:

according to the picture above this is how the mod will work:
customers spending 0.01 to 99 will have 5 shipping
customers spending 100-199 will have 10 shipping
customers spending 200-299 will have 15 shipping
customers spending 300-399 will have 20 shipping
customers spending 400 or more will have free shipping.
*NOTE - Be sure to input values from lowest to highest.
It provides 5 inputs for you to set prices. If you don't need them all that is fine, leave them blank. It will use the highest value you have set previously. Example: You set "Sub Total Minimum = 200, Fee= 10", but you have no higher settings. If someone spends 300, they will pay 10 shipping as well.
*The value for the first Subtotal Minimum is '0.01' permanently, since that is the least amount of money a customer could spend.
Here is a link to download the mod, just unzip and upload the contents of the 'upload' folder to your opencart root folder, nothing will be overwritten. Make sure you download the mod that corresponds with your version of OpenCart.
Version 1.4.7 - http://www.deviumrocks.com/download/Shi ... _1-4-7.zip
Version 1.4.8 - http://www.deviumrocks.com/download/Shi ... _1-4-8.zip
Let me know what you think guys and if you have any ideas on how to make it better.
thanks,
mtlhd
PS - Also, I wrote an update class that will update all your products by UPC (distributes the quantities by size). Send me a private message if you also have that problem and I will send you the code.