I have recently learned of the existence of an obscure punctuation mark known as an Interrobang. It is basically a combined question mark and exclamation mark and is used instead of ?! or !?
I must say that this could be rather a useful punctuation mark for me. Especially for use in texting. What‽ You mean you can't get it on a normal mobile phone‽ That's preposterous!
In fact, it doesn't even appear to be available in MSWord -- or, if it is, it's buried so deep that it would take months to dig it out.
For more information, see this Wiki entry.