To be a guard is considered one of the highest honors for a soldier. You can click here to read about what it takes to become a guard of the tomb. I've read a lot of articles about what is expected of the men who take on the task of being a guard. Quite a bit of it isn't true. I was surprised to see that their barracks are in fact on site below the Memorial Display Room.
Here is a link to a video of the changing of the guard. Note the precision of the ceremony.
Thank you to the men and women of all our armed forces for your service!