( Engadget ) - While executives can blow-hard the success of their goods 'til blue in the face, one of the best measurements of market acceptance is the appearance of the third party accessory. Here's the first we've seen: Kindle Cases from WaterField. Starting February 12th you'll have your choice of a $27 slip case, $39 sleeve case, and $49 travel case offering varying degrees of protection unmatched by any dust jacket. Then again, a book doesn't require much protection does it?