Justin Timberlake made a surprise appearance at the launch of the United Nations Foundation's new mobile initiative, mPowering Action, on Friday night (08Feb13) when he joined his producer pal Timbaland onstage for a performance of their hit song Carry Out. Guests at the Los Angeles bash included Twilight co-stars Kellan Lutz and Nikki Reed, and the singer's former 'N Sync bandmate Joey Fatone.