I can't say about the specific starter for Amish Friendship bread, as I have never used it, but for regular sourdough starter - the kind that is just flour and water and wild yeast - you can dry it. Smear some of it very thinly on a piece of wax paper or plastic wrap, and leave it to dry. Use an oven that has a pilot light, or turn on the oven to its lowest temp., and leave the door partly open, or use a dehydrator at a very low temp. If you live in a dry climate just leaving it on the counter should be OK. The point is to dry it quickly and at a low temperature, so as not to kill the yeasts. When dry and brittle break it into small pieces, wrap air and moisture tight, and store in the freezer; this is good as a backup, in case your "real" starter has problems someday. I would dry a new batch every 6 months or so to make sure it is viable. The dry chips can also be sent through the mail, well wrapped. If you haven't tried this before I would suggest drying some, and then reconstituting it in room temp. water mixed with some flour (leaving overnight to check that it still acts like sourdough) to check its viability before sending any off to friends. You don't need to dry very much; you only need a little to innoculate your flour/water mixture. It might be worth the experiment to see if it works with the special starter.