Grant Rettke over at Wisdom and Wonder has a useful post on how to get a 【Hyper】 key on any USB keyboard. As Rettke says, the 【Hyper】 key is the last modifier that’s available almost exclusively for users.
My Emacs life has been much better since I implemented a binding for 【Hyper】 on my Macs. To do that, I use the 【fn】 key that’s on all (the modern, at least) Mac keyboards. I learned how to do that from Magnar Sveen and wrote about it a few years ago. Rettke is also using a Mac but his solution is more general because it doesn’t depend on having a 【fn】 key. In particular, if you’re on a Linux or Windows machine, Rettke’s solution will work for you although you’ll need to change the binding for hyper to whatever is appropriate for your architecture.
If you’re an Emacs user and don’t already have some key mapped to【Hyper】 you should head on over to Rettke’s site and learn how to do it. Believe me, it will make your life better. And, you’ll get to see Wisdom and Wonder’s nifty new theme.