Manually clear saved question drafts
Sometimes, I start typing a question, then realize I just don't want to ask it (e.g., it's already been answered, I figure out the answer as I'm typing it, etc.).
I assume this is a pretty common scenario, but there's really no UI support for simply canceling or discarding a question. You can certainly leave the page by navigating away from it or closing the browser tab (and clicking "Leave Page" when the dialog appears), but then if you go back to ask another question later, the title and body fields are filled with data from the previous question. This requires you to manually delete all that junk before you can start typing your new question.
I realize this is not a huge burden or anything, but it does add an unnecessary level of complication to what should be a very simple process.
I propose adding a small cancel or discard button (or perhaps just a hyperlink) next to the Post Your Question button. Users would still receive a dialog to make sure they really intended to push that button, then they would be taken back to where they came from or the home page for the particular StackExchange forum they are on.
This would reduce the process of leaving the question editor and clearing the subject and message body down to just two clicks. It would also add only minimal clutter to the UI.
Note that, when you edit an existing question, there is a little "cancel" link next to the Save Edits button. I'm proposing that the exact same link be added for new questions.