The 7-Eleven website has more info on the Kwik-E-Marts, including where to find them, and what you can buy there, like Radioactive Man #711.
There are great Kwik-E-Mart photosets on Flickr. Check out photos of the Kwik-E-Marts in Burbank, Mountain View, and Bladensburg. See what these converted 7-Elevens look like inside and out.
Washington Post coverage.
Previously mentioned here and here.
Thank you, come again.