So there I am, typing a new question (or an answer). As it appears $\LaTeX$'ed in the preview frame, I keep improving it... and then I realize that there is some detail I need to think more about before posting it. When I close Firefox, it gives me a warning "This page is asking you to confirm that you want to leave - data you have entered may not be saved." So I (hopefully) copy my text and save it somewhere on my computer.
The next time I open my browser and hit "ask a question", there it appears already. Nice feature, I think - and keep working on it, until I realize that the last changes of yesterday had not been saved. Grrr... Nobody knows at what moment it has been saved the last time. it is claimed here that it happens every minute or so. But that is not my experience!
Couldn't there be a "safe draft" button? Or some "autosave every 5 min." feature?