MUJI is short for "Mujirushi Ryohin," which is Japanese for "No Brand Goods." Most everything MUJI makes appeals to my personal style--not because I'm not interested in brands (they fascinate me), but because MUJI products are simple and functional, yet elegant.
The MUJI Business Card Case holds not only my business cards but also my GRE vocab cards. The case is currently on sale at the MoMA store. Not only is this case cheaper than most of the business card holders I've seen, but I just plain like this one the best.
[Yes, I have business cards. The president of the Columbia Women in Business Society somehow convinced me I needed them. So far, I haven't absolutely needed them, but they do make me feel snazzy.]