Harry Potter and the Deathly Hallows was almost called Harry Potter and the Hallows of Hogwarts, according to a newly-released interview with J.K. Rowling from Melissa Anelli of Harry, a History.  Hallows of Hogwarts was one of the fake titles that Rowling sent to the publisher in order to keep the real title secret, but apparently it had been the actual working title of the book for years:

JKR: I sent them a list of plausible titles, including the real one. Hallows of Hogwarts for years was going to be the title of the seventh, and it was wrong, just wrong.

MA: They aren’t all of Hogwarts.

JKR: Exactly. It changed completely, so Deathly Hallows was definitely the right way to go. I like the title of Deathly Hallows.

MA: Some people said it was you getting back at people who criticize your use of adverbs.

JKR: [laughs] Yeah, about 12 adverbs in the final title. I love an adverb.

Hey, maybe that’s what they can name the second Deathly Hallows movie instead of just going with Part 1 and Part 2.  Eh?  Eh?