BEFORE AND AFTER, ON ABC NEWS' "20/20," FRIDAY, AUGUST 6

A man who lost 400 pounds and gained a new life, a bald model who wins beauty pageants, a man with an idea that catapulted his financial worth into the stratosphere, a wife who stunned her neighbors -- and her husband -- when she fell in love with another woman� "20/20" reports on "Before and After," FRIDAY, AUGUST 6 (10:00-11:00 p.m., ET) on the ABC Television Network.

Reports include:

· David Smith, a former friendless shut-in who once weighed 630 lbs, lost an astounding 401 lbs with the help of his first true friend, a fitness trainer named Chris Powell. Not only did Powell help with the weight loss, he was instrumental in helping Smith � painfully shy and awkward around women � hit the singles scene in search of true love. Smith's incredible transformation even led him to become a personal trainer himself. Chris Connelly reports.

· Miss Delaware, Kayla Martell, is not your typical beauty queen. She transforms in a matter of seconds from someone with a luxurious mane of hair to a bald beauty. Since the age of 10, Kayla has been fighting alopecia areata, an auto-immune disease that has resulted in severe hair loss. "There were times when I thought, is this really the right place for me? Do I belong in the Miss America Pageant? Is this ever going to happen for me?," Kayla told "20/20." Deborah Roberts reports on the transformative power of humanity over hair.

· The Super Soaker is more than just an object of child's play, it is a toy that transformed a life. Former NASA scientist Lonnie Johnson accidentally came up with the high powered water device while working at home, and a toy legend was born. For the financially struggling inventor whose marriage was on the rocks, the Super Soaker became the agent of change. John Berman reports.

· Shira Neuberger seemed to be the perfect wife with the perfect life -- a handsome husband, two beautiful daughters and a pretty house outside Philadelphia. But last year Shira stunned neighbors in her quiet suburb by splitting with her husband and inviting a new partner into her home. Even more surprising, the new love of Shira's life wasn't another man, but another woman. Elizabeth Vargas reports.

"20/20" is anchored by Elizabeth Vargas and Chris Cuomo. David Sloan is executive producer.