Is it possible to write draft posts on TEX.SE? It could be useful when you are interrupted and you don't have the time to finish your question/answer. In such cases, AFAIK, I don't think it is possible today to save the draft and finish later. (?)
Technically, you're allowed to try whatever you want in the Sand-Box. The formatting mark-down for questions and for answers is the same, therefore you can make your draft an answer in the sand-box. Just start it with something like:
This is a draft of a question for the main site, I'll use and remove it before December 25, 2013.
This should be IMHO fine. It's good to add the date there, and it's good to delete it once you don't need it anymore.
However, I'd like to know a moderator's opinion on my suggestion before you use it.
The author of a post (question or answer) can undelete his own post, as long as he closed it himself. If the community or a moderator voted to close/delete, then they will have to agree to undeletion.
Also, deleted posts don't show up in one's user profile, so it's necessary to save the URL to continue editing.
Still, this is an option for saving multiple drafts that aren't yet ready for public viewing.