USB Keys nowadays come in all sizes, and are decked out with some of your favorite characters. Haven't seen a Hello Kitty one yet, but Akihabaranews mentioned this USB key adorned with Japanese characters on both sides. This series of USB keys features DokoDemolcho and his posse who are popular in Japan, and have appeared in video games. The USB has a handy lanyard so you don't loose the cap, and transports about 128MB of music or other data. You can find it at IOdata.