While jQuery.sendFeedback is not a comprehensive reverse-engineering of the Google Feedback tool, it gets the core functionality down. The primary goal being the ability for users to highlight areas of a page and then submit a form sending the page with highlights along as an attachment.
I set out to create this tool because I feel that it is invaluable to get the most detailed data possible from your users and this interface is the perfect way to do that. Unfortunately the Google Feedback tool is not available to the public so a solid remake seems to be the only good option.
If you have any questions or would like to contact me you can email me at Alex@CodeTunnel.com.
Note: This plugin is still under active development. This page will be updated with the API documentation once I am confident we can release a version 1.0 of the tool.