JQuery :: Gather Form Data Into JS Object?

I'd like to know if there's any method to gather form data into a JS object, just as form POST would have sent it to the server. I think such method would be helpful to tweak the parameters a bit, before submitting it to server. Although I could do that via modifying 'value' of 'input' elements, I think it'd be helpful if jQuery can gather the post data in a JS object and return it (so that, for example, I don't have to traverse the form and deal with selection and radio button input elements)

Maybe we need a reverse function as well: given a JS object, do a POST with it, just as if there were a form with the said data, and it's submit were invoked (i.e. not via. AJAX, but load the entire page from the POST reply)