America's favorite form of birth control _ the pill _ celebrates its 50th birthday on Sunday. It was May 9, 1960, when the U.S. Food and Drug Administration announced approval of the first oral contraceptive.

Today, a world without the pill is unimaginable to many young women. They now use it to treat acne, skip periods, improve mood and, of course, prevent pregnancy.

Many historians acknowledge the pill as one of the most important inventions of the last century. It gave women more control over their fertility than they'd ever had before. And it permanently put doctors in the birth control picture.

But it didn't end unintended pregnancies. Nearly half of all pregnancies in America still are accidental.