There is a new, large Ralphs Supermarket here in Palm Springs, California. They have a number of GF foods that I don't usually see in other supermarkets. There are several brands of GF pasta, near the regular pasta. They also have a number of types of GF cookies, including Pamelas and another brand.
It seems like the larger regular supermarkets are beginning to take interest in the GF food market.
I've also seen a fair number of GF food items at some supermarkets in Worcester County, Massachusetts.
