Radar Online has a great pictorial essay on our collective fascination with the female breasts. Bras were invented 100 years ago, back in 1907, and since then the Western concept of the ideal breast has undergone many interesting transformations.

Here's an ad from 1965 for the "Fabulous Mark Eden Bust Developer". It featured slogans such as " A girl doesn't have to be flat-chested". The workout tool consisted of a giant clamshell-like device with a tight spring.

Mark Eden made claims such as this before he was shut down by the U.S. Postal service;

So many women who have been literally 'flat as boards' have achieved higher, fuller, lovelier bustlines in a remarkably short time with the Mark Eden method. And a woman whose bustline is suddenly transformed from the average or below average to a richer fuller development receives more for her efforts than just a larger reading on the tape measure. She is subtly transformed as a woman. There is an incomparable difference in the entire feminine line, shape, and grace of her whole figure. Her very presence takes on a new and subtle glow of womanliness, of sex-appeal, and yes, of glamour that is undeniable and unmistakable.