Club Nintendo Europe have recently introduced a series of different coloured "Power Up Pouches" into their Stars Catalogue for a cost of 2500 Star points each.
The perfect portable place to store your stuff!
This soft draw-string pouch with lined interior, decorated with iconic Mario power-up images, is the ideal way to store your Nintendo 3DS, Nintendo 3DS XL, Nintendo DS or any precious items you have to hand! Measures approx. 13 x 20,5 cm
Description from Nintendo Stars Catalogue [source]
Far from the most imaginative of Club Nintendo rewards, but like all CN stuff, cool in its own right and undoubtedly will be quickly snapped up by collectors. Personally, I'm waiting for a solid gold statue of Bowser.