From their web site:
The mission of Let’s Say Thanks is to provide a way for individuals across the country to recognize U.S. troops stationed overseas. By submitting a message through this site you have the opportunity to send a free personalized postcard greeting to deployed servicemen and women.
As part of my goal to send more cards, I’ve been visiting the site every day and sending a card. It’s very easy to do and costs nothing. You can choose from a list of messages or write your own. The hardest part for me is picking out which one I want to send.
Everyone knows someone, in some way or another, that is in serving our country. Personally, I have a cousin in the Air force, friends that are serving in Afghanistan and Iraq and many more friends that have served in the past in various branches of the military. You don’t have to support the war to support our troops. A simple thank you card can make a soldier’s day. It reminds them that they are appreciated and we are always thinking about them.
Drop the link into your bookmarks and take 5-10 minutes every day to send a card.