The design in the blue area has changed a few times, as the number of stars is supposed to represent the number of States. The stripes were also going to represent the number of States, but that design was abandoned pretty quickly. Now there are thirteen stripes, one for each of the thirteen original United States.
In my opinion, even though the vast majority of Americans don't (can't?) agree on anything, the flag binds us together as a nation. Any time we find ourselves in an "us against them" scenario, such as during World War II or 911 or, less dangerously, the Olympics, it's the flag that we can use as a symbol to "rally 'round." We know we're not perfect, but we're family. And our flag is one beautiful testament to 200 plus years of getting along pretty darn well.