Post_location_href_crx is a project mainly written in JavaScript, it's free.
test of cross-domain XML HTTP Request
test app for cross-domain XML HTTP Request.
% gem install crxmake
% rake -T
% rake
Drag and Drop ./package/post_location_href.crx to Chrome.
or
% open package/post_location_href.crx
It POST document.location.href to http://localhost:8888/page