Two excellent organizations that send care packages can be found at
www.anysoldier.com, and
www.OperationUSOCarePackage.org. The anysoldier group started out as the personal effort of one military mom whose son asked her to send a few things to some of the soldiers in his unit who never got mail. It has grown from there. The USO does great work too. I'm sure there are also other organizations that do the same sort of thing.