Trails-End has a program where they send popcorn to U.S. military forces overseas.  There are spaces on your son's order forms for $40 donations and $25 donations, but people can choose to give as much as they like.  Pack 4 will pool those donations and make a single payment to Trails End for military popcorn. 

People also have the option of making a donation to Pack 4, in any denomination.  Just make sure you understand if the donation is for the military, or for the local pack.