Nilly! That was very interesting to read.

Meanwhile, in Australia they've discovered a way to use HP to teach Mendelian Genetics!.

I was rereading Goblet of Fire last night, and I started wondering if maybe the Sorting Hat couldn't be a Horcrux. I just hadn't realized that it had been Gryffindor's before he enchanted it. Over the years, the hat has probably been guarded less strictly than Gryffindor's sword.

Yeah, I was wondering why the sorting hat didn't fall under the "don't trust anything that can think for itself if you can't see where it keeps its brain" rule.

An HBP A-Z in the style of Gorey. Or at least, the first 6 pictures of her WIP.

FABulous. Spoilery, obviously.

Honestly, it's kind of a bad rule. Half the scenery of the wizarding world thinks for itself without a visible brain. I mean, what about the Ministry of Magic phone booth, with its label-making technology?

I mean, what about the Ministry of Magic phone booth, with its label-making technology?

I don't see that as really thinking for itself. It's just recording information. The sorting hat actually makes decisions and gives advice.

It's just recording information.

If I'm recalling correctly, it makes some judgment calls. But I don't have OOtP with me, so I can't give evidence.

From the JKR interview linked somewhere above:

ES: Has the sorting hat ever been wrong?

JKR: No.

ES: Really?

JKR: Mm-mm. Do you have a theory?

ES: I have heard a lot of theories.

JKR: [laugh] I bet you have. No. [laugh] Sorry.

MA: That's interesting, because that would suggest that the voice comes more from a person's own head than the hat itself -

JKR: [makes mysterious noise]

MA: And that maybe when it talks on its own it comes from -

JKR: The founders themselves.

The only problem with either Gryffindor's sword or the Sorting Hat as Horcruxes is when would Riddle have had access to either of them? The sword had, presumably, been stored someplace unknown until Harry unintentionally summoned it from the Hat (or the Hat gave it to him, which is my preferred interpretation) in the Chamber, and the Hat itself never left the Headmaster's office outside of the first day of school until Fawkes brought it to the Chamber. If Riddle had been able to get that job teaching at Hogwarts, I'd be more inclined to think that he was able to get his hands on either or both of these objects. As it is, though, I'm inclined to think that the final Horcrux is something belonging to Ravenclaw.

Harry has been able to break into the Headmaster's office, so I think that Riddle could have gotten up there, too. Especially when he was Riddle and not yet Voldemort.

Is there any mention of the sword before Harry pulls it from the Hat? That seems like just the sort of object that JKR would show us early, to appear later.