You can order an Inauguration Flag through the Battleshop at the Battleship New Jersey.
"We would like to offer you the chance to Pre-Order your American Flag flown over the United States Navy Memorial on Inauguration Day 2009. The Navy Memorial is located on Pennsylvania Avenue, along the parade route from the U.S. Capitol to the White House."
They're taking orders until Monday, January 19th.
The flags are 3' by 5' and cost $34.95.