I was looking for a cover to protect the contacts of my Pentax K-5 batteries while carrying them in the pocket. The K10D batteries had such a cover to snap on but the K-7/K-5 batteries don’t have that.
So I decided to create my own cover that can be snapped to the bottom of the battery.
As a special feature, it has embossed labels “empty” and “full” each on one side of the cover. These labels together with the little arrow on the top of the battery can be used to distinguish used from charged batteries.
The cover was created with a 3D printer at shapeways. If you are interested, you can order it at http://www.shapeways.com/shops/birzer