Allow questions to be saved as drafts prior to posting
Some answers take a while to complete, and sometimes they require more than one seating for completion. It would be nice to be able to save answers as "drafts".
For example, say I have been typing an answer for the past 15 minutes, but I need to leave my computer for a while or switch to another computer. It would be nice to be able to save my answer so that I can edit it and finalize it at a later time.
I realize that I could just copy the text into a text editor and email it to myself or save it to my desktop, but I think it would be nicer to have the functionality built into the site. There have been times where I have been halfway through answering a question when I have to leave and I end up closing the window and not answering the question.
Update @Tim Stone pointed out that the system will automatically save a draft for you on a set interval. I was unaware of this feature -- somehow I never noticed it. Some other people have reported that the feature is somewhat inconsistent and/or unreliable.
I would tend to agree with @nhahtdh that since the functionality to save an answer as a draft already exists, there should be a way for the user to call the "Save" function themselves.