AFAIK you can. When you're writing a new entry, there should be three submission buttons: Post, Preview and Save Draft.
As a bit of an oddity, when you go back to edit your draft, you can't actually post it. You have to copy&paste to a fresh entry, but you can still use the same title and all. Then go back and delete the draft. It's a bit odd, but it works well.
Thanks for the suggestion WV! Got any others? Anyone else? Nice to see you around BTW.