A splendid idea, Greg. Receipts are pieces of everyday
ephemera that nearly everyone has exposure to. They
are design in its most omnipresent form.

I'll contribute by sending along a list of fonts that could
be used for the printing of receipts.

In a very basic way, they are designed. Someone
had to determine where the logo would go and
in what order messages would appear and how
purchased items and prices and totals would
align. Beyond that, they are designed by chance
and machine - and that can be interesting too.

That kind of design is my favorite one --- here, you have only these components/fonts/measurements/conditions... make what you can make of it.
Build a house with these seven bricks.
Make a painting with these four colors.
you know what I mean.
I was once involved in designing a ticket for the cinema, that was great fun. where should the price go, where should the movie title go, which text should be bigger, use font number 1 or number 3? hehe
Tepid Monkey had some nice receipt fonts, I remember.

>They are design in its most omnipresent form.

But receipts are not really "designed", are they?