I've located about a brazillion Callery pears in Ohio, and one wild crabapple. Next summer I'm planning a big effort to graft them over to useful varieties, especially Asian pears.
I'm planning to plant out a bunch of seedling Dolgo crabs at my place in Canada, and eventually top work the ones that thrive.
Here in Norway I have found a couple wild apple trees that I pruned up heavily this winter. They get a year or two to show what kind of fruit they produce before I start grafting to them. I've also started grafting apples for wildlife in sets of 3 on Antonovka. I have early, mid, and late season varieties I'm working with.
I also have a rather big seedling project that is ongoing. My supermarket seedlings are in stage 2 of their process, planted from their pots into a bed of loose soil/sphagnum blend. I'm now locating various Dolgos that I will collect apples from this fall, and use them for wildlife trees and rootstock.