The range of possible identities is no different than in the physical world. All the examples of personal transformation Turkle gives can be accomplished in the real world. The obese can be made slender through the use of liposuction. The beautiful can be made plain with unflattering makeup, a bad haircut and ugly clothes. The nerdy can be made sophisticated by learning how.
Women can be men.
We are now capable of transforming ourselves into almost anything we want within the bounds of our species. We have even started to push at some biological barriers. The rampant use of plastic surgery by celebrities is so extreme it has created an inhuman human ideal. Plastic surgery also allows us to recapture our youth. Bodybuilders have more muscular mass than is naturally possible thanks to anabolic steroids.