OMG an interrobang, my eyes can hardly believe it. Haha. I love the idea (I constantly use '?!' in online chat) but they don't look so great. Also, in chess, !? and ?! have different meanings..
This page (in the comments at the bottom of the page) has spanish-speakers using both that and the reversed version, and even the 'gnaborretni' (inverted interrobang) :
