I spent an afternoon at the Steven F. Udvar-Hazy Center with my son, Eamon. It was grand. The great American experiment continues. My father used to take us to the Franklin Institute, the U.S. Mint, the Liberty Bell, National Constitution Center (then Constitution Hall), Carpenter's Hall, the Betsy Ross House, Penn's Landing, and other cultural sites in Philadelphia when we were young, and I have continued that tradition raising my sons.
Eamon had a blast. He liked it all, but especially the Space Shuttle, the WWI planes, and the .50 caliber machine guns. I highly recommend a visit, especially if you have children.
The Imax movies are not to be missed. We saw Aliens of the Deep, which explores the creatures of a world we rarely visit or see, the deep ocean two miles down.