From NY Post:

Dr. Jacobs said he can turn even the flattest rump into a celeb-worthy humps with a little help from your extra padding and about $11,000. "It's your own fat, and it's in the best soil [your butt], so it lasts," said Jacobs. "The added bonus is they're getting liposuction to get the excess fat and put it where you need it," he said. American Society of Plastic Surgeons statistics show that butt lifts have increased dramatically, up 283 percent from 2000 to 2005. Business is certainly booming at some Big Apple offices. "We're doing four, maybe five a week on a busy week," said George Lefkovits, of Manhattan. "It's now become one of our key operations in the office. "You can do this on a Thursday or a Friday and be back to work on Monday," Lefkovits said. Some complications can include infection, lumpiness and unevenness. Critics also contend that the fat doesn't stay in the posterior for long, and most people will need to be retouched as time passes.