From my wife who isn't setup to be able to post at the moment:
---------- Forwarded message ----------
Walmart's brand Sam's choice Real Semi-Sweet Chocolate Chips are pareve (milk 
free) but not all Walmarts have them.

We use Tropical Source semi-sweet chips from the local health food store. You 
can see it at

http://www.worldpantry.com/cgi-bin/ncommerce3/ProductDisplay?prmenbr=172832&prrfnbr=457241

They make a point of saying it is "manufactured in one of the only chocolate 
factories in the world that has dedicated production equipment that is never 
used with dairy or gluten ingredients."  They have a line of chocolate bars 
too.