Recently, a friend (who is also a word-nerd) posted something on Facebook that totally caught my eye. And, while I'd never actually seen one before, I intrinsically knew what it was.
In this age of emails and texting we write to each other more than we talk - and we need to find ways to express emotion so that our meaning doesn't get lost in the print. When I'm trying to express incredulity or surprise, I often use an exclamation point followed by a question mark (or vice versa). The interrobang was introduced in 1962 to represent this exact combination of punctuation. It was used, primarily, in advertising for the next couple of decades but never made it to popular usage. The Wikipedia entry is fascinating and will send you down the rabbit hole of weird, unused punctuation.
I vote that we resurrect the interrobang. Who's with me‽