Get working multiarch on debian testin: is it possible?

Hello, All.

I read that Debian Testing/Unstable and Ubuntu 11.10 support multiarch. 
As I read, in order to get multiarch in Ubuntu, I need write 
"foreign-architecture i386" to /etc/dpkg/dpkg.cfg

But it does not work in Debian Testing for now. After it dpkg prints 
this message:

dpkg: error: configuration error: /etc/dpkg/dpkg.cfg:15: unknown option 
'foreign-architecture'
===============================

Is it possible to get multiarch on debian testing? What can I do in 
order to get it?