Woot! I thought they were out of season, but apparently they are still available. This is a good site to start sampling heirloom apples:
http://www.applesource.com/
Check out this smithsonian page for other possible sources.
http://www.smithsonianmag.com/smiths...02/apples.html
Better get started - a nursery site from that page indicates that there are over 450 varieties just in the south!