Operation Backpack is still in full swing. If you are interested in participating, they have a facebook page at https://www.facebook.com/events/256056051399131/ . Finding a direct contact for sending materials may prove tricky, as there is no formal organization other than the volunteers here and in Kabul. If you are interested in helping support the program, message me and I will send you information that might help. If you have more info, please share it in the comments section!