I recently got a Nook (the Barnes and Noble e-reader), and I thought, "Well, this definitely needs a cozy!" I just kind of made the pile of flesh up as I went, and I think it came out pretty well. I don't own a Kindle, but based on the measurements I've found online, I think this cover would work just as well for a Kindle. So, here are the pics:
Here's the pile of flesh:
Use whatever worsted weight yarn you like, and with a G hook, ch 33.
Row 1: dc in 3rd st from hook, dc across
*Row 2: dc (fpdc, dc) across, ending with a dc
Row 3: dc (bpdc, dc) across, ending with a dc
Rep from * until piece measures about 10 inches. Fasten off (or, if you're lazy like
me, just keep going with the slip stitches you're about to use to join the piece).
Fold the piece in half with the wrong sides together (e.g. the ribs should be on the inside). You should
have a shape by now that pretty closely matches your e-reader.
Join the short edge along the top with a slip stitch, and repeat with the bottom edge. If you want to
avoid fastening off and weaving in ends, you can just carry your yarn across the inside using a slip
stitch until you reach the other side.
Turn piece right side out.
Finishing the opening:
Row 1: sc around
Row 2: sc around
Fasten off, weave in ends.
Hope you like it!