Hey, the Iraq & Afghanistan Veterans of America get real stuff done for vets, like educational and medical benefits.
They encourage you to join a vets march if one's near you, but also, you can show your support on Facebook by using their app, which joins them in a week long virtual march. It sets your Facebook status to genuinely support the troops each day, like:
I don't know, but I've been told, your Facebook status is worth more than gold. March online with IAVA to honor the service of new vets and show them you've got their back.
Beyond that, the IAVA provides real help for the troops every day of the year, which we all gotta do more of.
Disclaimer: I've joined their board, in part, since they get stuff done.