Well, cosplayer Enji Night (the girl in the picture, duh!), seems to be a big fan of Mario and decided to dress up like my favorite video game plumber! There is all kinds of gaming greatness in this picture, but I have to say that I am kind of jealous of the mushroom necklace. It might seem kind of big although I think I would probably prefer to wear something like that over the Gears of War dog tag that I currently wear just because Super Mario Bros is much more recognizable.
Official Source: http://fashionablygeek.com/costumes/its-a-me-maria-cosplay/