Many times I have been asked by folks back in the US "What can we do to support the troops?"
When asked, I'll try to find out more about the person asking (isn't it common for rabbi's to answer an question with a question?) and help them figure out what would be a good fit. I lean towards getting them interested in doing something local (ie. think global act local) such as visiting a local military post and doing something for military personnel there.
The Jewish War Veterans is a great organization that actively supports Jewish programs on military installations all over the country. They make a big diffference for the Soldiers, especially ones in basic training and at the military academies. Local JCC's can offer memberships to military families at reduced rates, and Synagogues and Temples can make a direct effort to invite local military families to participate in their communites.
Soldiers are trained to handle the challenges of combat, but they do best when their families are doing well.