Does anyone make a spacer for SPD cleats? I have a pair of cycling shoes that accept a two-bolt cleat, but require a spacer between cleat and sole to be compatible with Shimano SPD pedals. My pedal and cleat package did not come with spacers.

Does anyone make spacers of varying heights for such a situation?
As Kibbee said, making your own out of a milk jug or soda/beer can is probably the easiest way to go.  The spacer doesn't need to have the exact same footprint as the cleat to work, so you don't need to be too concerned with the sizing/shape.