After a long, fulfilling life that included a Grammy win, a run atop the Hot 100 and countless appearances on dance floors worldwide, the song "SexyBack" will finally retire from the pop music world. At least that's what Justin Timberlake said last Friday in Las Vegas at the "Justin Timberlake and Friends: A Special Evening Benefiting the Shriners Hospital for Children." Joining Timberlake at the event was an all-star cast that included 50 Cent, the Jonas Brothers, Rihanna, Maroon 5's Adam Levine, Leona Lewis and Lionel Richie. The night also featured a duet between JT and Levine, as well as Justin collaborating with Will.I.Am and Richie on the Commodores' "Easy." As for penning new hits to fill the void left by the retirement of "SexyBack," Timberlake said he'd prefer to concentrate on writing some songs for artists like Rihanna and Lewis.