where could I find RF Shield bag? (CA, US)

Hi,
I'm looking for a RF Shield bag, that will block cellular frequency (1GHz) from the outside.
The size of my unit is just a little smaller than a laptop.
Do you know where I could find one of that size?

I'm located at CA, US.

Thank you very much.

You could use some aluminium or copper mesh to make one, the finer the better. What kind of attenuation do you need to achieve?

http://www.ramseytest.com/

You might also try a microwave oven chamber.