I am in the process of developing a plugin that will consume the Webgistix API. Webgistix is an order fulfillment company, sorta like shipwire. You sign up and pay them god knows what to hold your inventory and handle shipping your customer's orders out.
I am creating it for a client, to be used in conjunction with the wp-ecommerce plugin.
Firstly, If someone else has done this before, I would love to see their work.
Secondly, Is there a proper way to hook functionality (for example my api) into a thrid party plugin (again for example, wp-ecommerce)?
Thirdly, If no one has done this previously, is there any interest in the community for this sort of thing? Should I release it when I'm done?