Integrating Shipping with Ruby on Rails

What is the best method to include shipping quotes in my cart?

The basic flow of my site is that

1.) User selects products  
2.) User is shown cart  
3.) repeat 1 and 2 until User wants to pay  
4.) collect user details ( email, address where items will be shipped to )  
5.) make payment via active merchant  
6.) order is submitted to distributor.  

I would like to insert a shipping information, so that the user can pay for his purchase + shipping costs via active merchant.

1.) User selects products  
2.) User is shown cart  
3.) repeat 1 and 2 until User wants to pay  
4.) collect user details ( email, address where items will be shipped to )  
5.) calculate the cost of shipment, a开发者_开发百科dd cost to cart, show to user;
6.) make payment via active merchant  
7.) order is submitted to distributor.

Is there a gem or plugin to help me here, if not... how can I get this done?

Thank you

Stefan

Check out the active_shipping gem:

http://github.com/Shopify/active_shipping

Its another extraction from Shopify (like ActiveMerchant)