I take my Kobo everywhere - just throw it in my backpack when cycling or tramping pack when going into the hills. I wanted something with rigid protection but couldn't find anything (might be something now though).
Ended up making my own out of a DVD case. Took a bit of work and several trys to get it right. Used a craft knife to cut out the extra bits plus a space for the pad button. Added an extra DVD case piece to strengthen the side that held the actual DVD which I'd cut out. Also added a piece of felt inside to the screen-side of the case with double-sided tape. Finished it off by printing a DVD cover sheet - with pictures of lots of books on it (also hides all the cutting I'd done).
DVD case is perfect size and they have a snaplock type closer. works a treat.