Look in the yellow pages for your nearest steel merchant.

I presume when you say metal you mean steel, rather than any other kind?
Aluminium? Copper? Lead? Titanium? If it's only 1mm thick or so, then a
jigsaw with a fine metal cutting blade will cut it with no problems.

Yes steel! Or perhaps that stuff that wolverines claaws are made of.

Will a steel merchant care that I only want a teensy bit.

Regards
Stephen