Quick update because as it freaking turns out, I've got shingles and it kind of freaking hurts to type. Having shingles, however, caused me to wonder why in the hell it's called shingles. I mean, it looks nothing like shingles, so I'm guessing that's not it.
Turns out, according to the good old online etymology dictionary, comes from Latin cingulus, for girdle, because it goes around your body like a girdle. Amusingly, cingulus comes from the Greek zoster, also meaning girdle. That's funny to me because the name of the disease is herpes zoster.
I know it's not the bad kind of herpes, but I still feel dirty having a disease with herpes in the name. Which comes, by the way, from the Greek herpein, meaning creeping.
For the record, my shingles look even less like a girdle than they do like a roof.