Fireworks explode above the Lincoln Memorial, the Washington Monument and the U.S. Capitol on July 4, 2006. Similar displays are set off every year in cities and towns across the United States to celebrate American Independence Day.

New colors such as lemons, peaches, fuchsias and deep purples and patterned shells – fireworks that go up and explode into recognizable shapes – are popular, and in 2007, a see-through three-dimensional box will debut in Washington. Other shells bursting through the skies this year on Independence Day might explode into the shapes of hearts, stars, smiley faces and sunflowers.

According to the American Pyrotechnics Association, companies that design and put on the fireworks displays increase their number of employees tenfold in the weeks leading up to Independence Day. (© AP Images)