At my small-town hardware store, they'll make it
for you on the spot,
as they have tanks of CO2 around.
Great for when you want to get part A into part B, and part A is just
a tiny bit too big.
Anyway, I received one email response so far to my inquiry to some of
the larger supermarket chains, and yes, they indeed will sell dry ice.
You have to ask for it.
And I figured this out from across the ocean. Ain't the Internet grand?
--
Will