Several people asked about using covers for other devices. I tried several covers I've used in the past but the only one I have that sort of fits the Kobo Aura is one cover for the Sony PRS505.
The PRS505 is an older model but these covers are still available from m-edge. Mine is blue but there are about a half dozen colors.
http://www.medgestore.com/shop/prs505/go
As you can see, the Aura is a tight fit. Be warned that this type of cover tends to spring open unless you wrap a band around it. It can be bent over so the front cover is against the back cover and that tends to losen it up some.