A childhood friend of mine became a Navy Seal, and recently lost his life a few months ago as his helicopter was shot down over Afghanistan.
I had seen him a few months earlier at my sister's wedding... the next thing I know I get a call on my cell phone from my sister telling me that it was his SEAL team that was shot down, and to turn it to CNN. Sure enough, the next day they released the names. It brought the war to my doorstep and drove home to me the sacrifices that people are making.
So yes, to echo WSkin's remarks, if you meet a SEAL, thank him. That job is no joke, and it takes a lot more than physical attributes. A whole lot more.
He was a great guy... one of the finest you'll ever meet.