I wonder how difficult it would be to add a "Rot13 this" button to the options under each text item (that is, next to "Vote up" and "Vote down" and so forth).
That would significantly reduce the nuisance factor associated with reading r13'd posts, without the site having to give up whatever value it is people see in using them.
Not that I'm offering to write the code, or anything actually useful like that. Just ruminating.
That's much too much work, and it'll be pretty bad for the website. It'll require another database query for every post on every thread (which means the site will be slower and more expensive), but it'll only be used on, what? The Harry Potter threads and the occasional brainteaser?
Textbook example of overkill.
EDIT: I misunderstood the request. I stand by it being overkill, though.
[Update: and now there's a fifth discussion thread, which you should probably use in preference to this one. Later update: and a sixth -- in the discussion section, which is where these threads are living for now on. Also: tag for HP threads in the main section, and tag for HP threads in the discussion section.]
The third discussion thread is above 500 comments now, just like the others, so it's time for a new one. Predecessors: one, two, three. For anyone who's been on Mars and doesn't know what this is about: it's Eliezer's remarkable Harry Potter fanfic.
Spoiler warning and helpful suggestion (copied from those in the earlier threads):
Spoiler Warning: this thread contains unrot13'd spoilers for Harry Potter and the Methods of Rationality up to the current chapter and for the original Harry Potter series. Please continue to use rot13 for spoilers to other works of fiction, or if you have insider knowledge of future chapters of Harry Potter and the Methods of Rationality.
A suggestion: mention at the top of your comment which chapter you're commenting on, or what chapter you're up to, so that people can understand the context of your comment even after more chapters have been posted. This can also help people avoid reading spoilers for a new chapter before they realize that there is a new chapter.