What do you call the falling blocks in Tetris?

[Kasz216]

Tetrazoids!

http://www.youtube.com/watch?v=1ZV9IlTJcIg

No, seriously i'm not sure i've ever had to refer to them. Outside of individually.

"L Block"
"Stright guy"
"Box"
"Revere L"
"The Z"
"Reverse Z"
and
"Crazy Pete"

I knew Tetrads was the correct name however.