When your head connects with your desk. Often used in online chat as an expression of frustration or disappointment.
Person 1: Does anyone know the webmaster's email address?
Person 2: Wutz a wbemastr???
Person 1: ....the person who designed this website...
Person 2: o.
Person 2: Wutz a email adress??
Person 1: ..........
Person 1: *headdesk*
1) The vitrous mineral Calcium Aluminum Silicate Hydroxide.
2) A villain from the anime Sailor Moon named after said mineral. In the original subtitled Japanese, the Dark Kingdom general Zoisite was a male, but English dubbers made him a female due to his homosexual relationship with another general, Kunzite.
An english romanization of the Japanese word for "bean" popularized by the relatively new but well-known anime Fullmetal Alchemist, in which people make fun of the main character's shortness by calling him by that word.
"WHO'S A LITTLE BEAN THAT YOU NEED A MILLION MICROSCOPES TO SEE CLEARLY?!!"