I'm working on a project where on certain pages (e.g. settings pages) we combine AJAX and regular fill-out-the-form-then-submit POST based operations. I'm curious if anyone has advice on improving the usability of such a page. One of my ideas is that when the user enters/modifies a value in a non-ajax part of the page, some sort of div would appear (say in a fashion similar to Growl) indicating that the user needs to save by pressing 'Submit' at the bottom of the page (and possibly putting up a modal dialog if the user navigates away from the page before saving, though that might be a bit too intrusive). I'm sure this type of interaction exists, but I can't find any examples.