Vodafone’s V501T uses what Vodafone calls “Costume Covers.” There are a total of twelve: Polygon, Soda, Tile, Bull, Tire, Cheese, Sucker, Lawn, Gummi, Wave, Mermaid, and Dinosaur Egg. Another interesting feature of the 501T is called “Panel Receiver,” which turns the display itself (a 2.4″ 240 x 320 screen) into a speaker for hearing the other party when in noisy environments (like anywhere in Tokyo, ever). It of course has the standard miniSD slot and 1.31MP camera expected of modern Japanese handsets, but Vodafone also adds “Simple Mode 3” for those less technical.
Press Release (PDF) [Vodafone]