Since 1948, the Tomb has been guarded 24/7, 365 days per year. This honor is held by the US Army 3rd Infantry Regiment, The Old Guard. This is one of the most sought-after duties, and is held by only the most distinguished. For 30 minutes to 2 hours at a time, a soldier will walk back and forth before the Tomb. Specifically he will take 21 steps, turn and pause for 21 seconds, and repeat. This is to symbolize the 21 Gun Salute, the highest honor granted to the fallen. These soldiers are held to the absolute highest standards of appearance, presentation, discipline, and decorum. Everything that they do is perfect. Whether on duty or off, they are not to do anything that would dishonor the Tomb.
Lem's Place: America, Memorial Day
AoSHQ/J.J. Sefton: Lest We Forget and Truscott's Apology
Twitchy: The History of Memorial Day via Arlington National Cemetery
Mark Steyn: Memorial Day and Decoration Day and Memorial Day in New Hampshire
Instapundit: Why Red Poppies?, Thank a Veteran, 10 Reminders of American Bravery and Courage
EBL: Easy Company enjoying Hitler's wine at Eagle's Nest, Women Who Served in WWII, Nurses and Doughnut Dollies of Vietnam and Korea, Women who Served and Died in Combat,...
and a selection of a few other National Cemeteries: Eagle at Fort Snelling Nat. Cem., Fort Rosecrans Nat. Cem., Yellowstone Nat. Cem., Confederate Rest, National Mem. Cem. of the Pacific, Guam Veterans Cem., Sarasota Nat. Cem., Massachusetts Nat. Cem., Puerto Rico Nat. Cem., and Nat. Mem. Cem. of Arizona