I am a huge fan of my M-Edge Guardian Case (a floating, waterproof and nearly indestructible case for the Kindle 2). But the Guardian case is no longer made or sold and we are 4 generations past the Kindle 2. Recently I stumbled on a new waterproof options, Waterfi’s Waterproof Kindle Paperwhite. Waterfi takes a regular Kindle Paperwhite and waterproofs it. You can buy a new Kindle Paperwhite with Waterfi’s waterproofing for $219 ($100 more than a regular Paperwhite). Waterfi also sells waterproof iPod Shuffles or Nanos and Nike+ Fuelbands.
Len Edgerly of the Kindle Chronicles has a video demonstration of it below.