Justin Bieber and Selena Gomez got in more tanning by the pool in Cabo today. Selena wore another bright bikini after lounging with shirtless Justin earlier this week. The couple have had plenty of time to relax during their Mexican vacation, but the trip also included an exciting celebration. Selena was a bridesmaid in her friend Shannon Larossi's wedding yesterday, and while the newlyweds took postceremony pictures, Selena and Justin kissed on the beach. Their fun in the sun will soon come to an end, though, since Justin is heading to the capital for the annual Christmas in Washington show. Justin performed for President Obama during the event in 2009, and this year he'll be featured again, along with Conan O'Brien, who's set to host.

Katy Perry is set to host SNL tomorrow night, but today she was joined by Matt Damon, Val Kilmer, and Andy Samberg on the streets of NYC to film a skit. Katy kept her new haircut hidden under a brunette wig and put on her best smile for the camera. Katy joked about hosting SNL, saying, "I'm up for a challenge, for something new. I love to be challenged . . . I married Russell Brand." Matt's been the featured star on the late-night show in the past, but this time he's just stopping by for a digital short. He's been busy promoting his upcoming holiday release, We Bought a Zoo, and even stopped by The Late Show this week to chat with David Letterman. Matt's made a habit of doing his best Matthew McConaughey impressions during past visits to the talk show, and this time was no different. Damon lightheartedly channeled the other famous Matt after some coaxing from Dave.

Blake Lively wore a vivid green Burberry Prorsum jacket for her visit to NYC's brand-new Apple store earlier today. The Grand Central Terminal location, Apple's largest outpost to date, opened with a crowd of thousands eager to get a peek inside. Blake was one of the lucky shoppers allowed to check out the techy gadgets like the iPad 2. She might be considering a holiday purchase for loved ones, or even picking up the coveted tablet for boyfriend Ryan Reynolds. Blake and Ryan spent a romantic weekend together near Park City, UT, over the Thanksgiving break, but for now Blake's shooting Gossip Girl on location in NYC while he's wrapping up a big-screen project in Boston.