Apparently, my favorite GF bakery, Glutenus Minimus in Belmont (they did my wedding cake), now offers GF pizza. From Mommy Poppins:

Now, every Tuesday, Wednesday and Friday, from noon until whenever they sell out, you can buy slices of gluten free pizza on that wonderful crust at Glutenus Minimus for $4.25 a slice. It’s a bit pricey, I know, but it’s worth every penny.