Tonight, I thought I'd try one new blog thing before going to bed: I decided to try installing a comments-feed generator called Feed Manager.
I installed it without difficulty, but when I went to enable it, I wasn't really sure what all the settings did. The screen snaps on the Getting Started instructional web page didn't seem to match the options I was looking at.
But I decided to play with it anyway, being careful to pick only templates I could restore if they were damaged, like the Atom and RSS templated.
But I must've done something wrong, 'cause it overwrote my main index page template, making it impossible to view my blog.
I found a copy of that template from two weeks ago, so as an emergency half-measure while half asleep, I set things up to use that copy. I think it's either the same as, or pretty close to, the one that got wiped out.
Next step: figure out how to reliably back up my MT templates before proceeding any further.
Anyway, the main reason I'm posting this is to say that if you see any strange behavior, you should let me know.
This may also have broken the LJ feed, but I'm too sleepy to deal with that tonight.