Owner's comments
This tree was on our property when we bought it in 1990. I would guess that it is at least 70 years old.
I am still trying to find out what kind it is. I will post pictures to http://home-and-garden.webshots.com/slideshow/574529896JFpGyf
The tree is completely hollow (probably due to ice damage and subsequent decay), but still produces a lot of smaller but delicious apples.
Update 2/8/10: The tree broke in half during a wind storm about a month ago. I am going to cut it just above the break and hope it sprouts new branches. Also I have determined that the variety is "Winter Banana".
Update 10/16/12: The tree did not recover, it is gone.