Hot shoe mounted polarizer/viewfinder?

[alvin]

Does anyone know where to find one of these?

http://www.kenko-tokina.co.jp/news/0110161.html

I think it's a viewfinder with a polarizer built in, so you can transfer the rotation angle to the polarizer on the taking lens. I'm right now just holding the polarizer in front of the taking lens, a bit ma-huan!

Thanks!

Alvin