So the cheapest solution in the world (per my own experience and the Internet) is a padded bubble envelope. I had just ordered a book or DVD set that came in a suitable envelope. I wanted something hard to protect the screen (bubbles aren't quite hard enough) so I taped some foam board that I had lying around to one side. But I wanted something more interesting, and figured I could do a collage or something on the envelope. Excellent idea, but I didn't have much around to collage with. What I DID have was a super-cute gift bag my former office-mate/current friend (though she's too far away now!) put a sweet Christmas present in. So I brought out the packing tape and the scissors and got to work! It added a lot of bulk and weight to the "case" but I think it was totally worth it.
Even though when I carry my Kindle I now feel like I'm going to a child's birthday party. "Sail ho! me squiffy men" indeed!
And while we're being crafty, here's a homely unicorn I made for her going-away. She likes unicorns more than I do (I prefer winged horses/pegasii only because they are, oddly, rarer!). I am pretty sure I like drawing homely unicorns more than she likes receiving them, but she does like homely unicorns, so yeah. Felt, yarn, buttons, and stuffing. Did not take long.