Aniketos,
Yes, they ARE young but we all were once and it makes me proud that the youth of today are still "kick-ass!" I didn't mean to infer that just because I have a knife to send, that I am better than those that don't. I just think that our troops could use some knives. Send the BEST you are capable of.
Good point as to WHAT type of knife to send! As a vet, I can say that a good all around fixed blade would be in order. One that would serve equally as well to open a can, a letter, spread peanut butter or a...well, you get the idea! It doesn't matter in what capacity one of our troops are serving and it wouldn't matter the size of the knife but I would say about a 4" blade or larger. Either a leather or kydex sheath would be fine because they are not in a tropical climate like Nam. I like your idea of a Leatherman tool or the like because I'm sure any or all would be appreciated but remember, a fixed blade wouldn't need sand cleaned out of it!
Get an address of one of our troops. If you don't know how, go to a local church, USO or write or call your local newspaper. Then write him or her and ask them what they would like. I'm sure you will make a friend for life!
We're all in this for the long term now and we need to do what we can to support our troops and what could be better than sending them a great tool such as a knife!