thanks everyone for the information, but I am not looking for queso fundido. I used to live in Southern Illinois and there was a mexican restaurant that had a thin, white cheese dip called "chili con queso" and it was great. I have never been able to find it in Chicago, but I did find a restaurant way out in Aurora called Friaco's that has a white cheese dip - but Aurora is too far to drive.
A few more details about the cheese dip itself, in case you're not
immediately familiar with it. It's hot, white, melted cheese dip,
typically served in a bowl of some sort, and often used for dipping
with chips and/or flour tortillas. Usually it contains very small
bits of jalapenos for flavor, though I've been a few places that offer
it with or without jalapenos (and they're usually *very* small bits,
not big chunks). I've read that it's typically made using Asadero
cheese, but don't hold me to that.
It's definitely not the same thing as Queso Fundido. From my experience, Queso Fundido is more of a dish than this dip, and tends to clump together and harden quickly as it cools. This white cheese dip is a very creamy, liquidy cheese dip that is offered separately as a dip for chips, etc., but also often comes on top of nachos, burittos, enchiladas, and other dishes where melted cheese is called for.