FINALLY got an e-mail response from visitor services at the National Archives with our reservation.

The date/time is Friday, August 14 at 10:45 am.

Ugh...not so good. Oh well...I can work with this!
So, without further ado, here's our final itinerary:
Thursday, August 13 (travel day):
Check in to Embassy Suites and get settled in room
Swim a couple of hours then get cleaned up, check out the local area and find someplace for supper
Get to bed early (no later than 10:00)
Friday, August 14:
Breakfast at hotel
National Archives - reservation @ 10:45 (hoping to be out of here by 11:30 so we can beat the lunch crowd)
Lunch at either the Pavilion Café or Cascade Café in the National Gallery of Art
Library of Congress (guided tours @ 10:30, 11:30, 1:30, 2:30 and 3:30)
International Spy Museum (closes @ 7:00 p.m. and last tour is @ 5:00)
Return to hotel; supper; swim before bed?
The Cascade Cafe is very conveniently located to the National Archives. This is where we ate on our trip. The food was very good and the cafe was not crowded at all. The Library of Congress tour was one of the highlights of our trip. The docent was an excellent story teller and kept the attention of my 11 year old daughter. Be sure to watch the National Treasure movies before you go. After the National Archives be sure to pop into the gift shop their to take your photo of the scene where Nicholas Cage is accused of trying to steal a souvenier copy of the Declaration. My kids loved that! You also see the Library of Congress Reading Room in movie and it will help to make the visit there more meaningful for your kids.
Saturday, August 15 (this day will be done with Tourmobile):
Breakfast at hotel
Arlington National Cemetery
Lunch at Old Glory BBQ
The Mall (FDR Memorial, Jefferson Memorial, Lincoln Memorial, World War II Memorial, Washington Monument, 56 Signers of the Declaration of Independence Memorial, Iwo Jima Memorial and Korean War Veterans Memorial) *will do what can realistically be done
Return to hotel; supper; swim before bed?
We did Tourmobile at Arlington and it was very good. But I would like to recommend Bike the Sites to see the Monuments. The kids and I loved this and it was one of the highlights of our trip. We did the Monuments at Night tour and it was excellent. You bike the Mall and see the monuments, you have opportunites for photos, etc. The guide gives you a brief run down of all the monuments and memorials. My kids loved the novelty of riding bikes on the mall.
Sunday, August 16:
Breakfast at hotel
National Space Museum
Lunch at either Old Post Office Pavilion of Start and Stripes Cafe
Hirshhorn Sculpture Garden
Ride the carousel
National Museum of American History
Return to hotel; supper; swim before bed?
I would recommend seeing the American History Museum first. There are ques for the Star Spangled Banner, First Ladies, and Pop Culture exhibits. We went to this museum at opening and saw these exhibits first. By noon there were lines of people waiting for each exhibit and we were able to simply walk in. There were not any ques for exhibits at the Air and Space museum that I recall, so you can sort of make your way to each exhibit with out having to wait. I might think about this order:
Breakfast
National Museum of American History
Lunch (perhaps at Air & Space the food court is McDonald's/Boston Market/Pizza)
National Museum of Air & Space
Hirschhorn
Carousel
or
Breakfast
National Museum of American History
Lunch (American History has a decent lunch but my kids preferred the McDonald's @ Air and Space.)
Carousel
Hirschhorn
Air and Space
Monday, August 17:
Breakfast at hotel
National Zoo
Lunch at one of the cafes at the Zoo
National Museum of Natural History
Butterfly Pavilion @ Museum of Natural History
Return to hotel; supper; swim before bed?
Tuesday, August 18 (departure day):
Breakfast at hotel
Mount Vernon
Head for home
I still need to get our tickets for Tourmobile, Spy Museum, Butterfly Pavilion, Washington Monument and Mt. Vernon and we'll be all set! Oh, and I also want to print out information on the exhibits at the various museums so Clay and the girls can pick out what they want to see. The bag I ordered should be here Friday so I'll be checking it out and figuring out how much it will hold.
It occurred to me the other day I might need to buy one or two more SD cards for my camera. I've got two already: one 128 MB and one 2 GB. Do ya'll think these two will be enough or should I get another 2 GB just to be on the safe side? And, of course, I'll need to buy a couple extra batteries for the camera and make sure I bring extra batteries for our handheld fans.