Question about these things: { }

They're generally called "braces" (brackets are [these things]). Checking the Chicago Manual, I see only mathematic uses for them.

They're also used in programming a lot, fwiw.

Hmmm. I think "wavy brackets" is the Southern U.S. vernacular. :)

I've seen them used (rarely) to distinguish nesting levels in intricately parenthesised sentences (like {to put forward a hypothetical example} this). Though I can't say I've seen it more than a very limited number of times (I think there's a few in R. Hume's Treatises, but he also uses extensive footnoting, to the point there's a few pages with a few lines of body text and mostly footnote text).

I've almost always heard them called curly braces or curly brackets.

Yes, they are called braces. And you can generally disregard them, because an extra set of parenthesis tend to work fine if you need to double enclose something.

Adam is right. They're used a LOT in programming.

At http://itre.cis.upenn.edu/~myl/languagelog/archives/000685.html
in the MIT Bookstore's letter is a use of braces, to let the smiley stand out I guess.

I call them "wavy gravy, " but then I also call hamburgers "Steamed Hams."

Furthermore, the Northern Lights sometimes appear locallized in my kitchen.