People.com Celebrity Star Tracks: Thursday, October 7, 2010 By People Staff Published on October 7, 2010 05:00 PM Share Tweet Pin Email 01 of 15 A 'NOBLE' EFFORT Luiz Martinez/Broadimage Nicole Richie takes a break from signing copies of her second novel, Priceless, to strike a sexy pose Wednesday at a Barnes amp Noble in The Grove in Los Angeles. 02 of 15 WEIRD SCIENCE Michael Murdock/Splash News Online Actor-musician Justin Timberlake tries his hand at a new calling Wednesday – science! – during an appearance on Spanish TV show El Hormiguero with Social Network costars Jesse Eisenberg and Andrew Garfield (not pictured) in Madrid. 03 of 15 PATTERN PLAY B. Ach/INF Khloe Kardashian and big sister Kim hit the red carpet in coordinated animal prints Wednesday for The Spin Crowd's season finale party in New York. Also in attendance: NJ Housewife Caroline Manzo, who suggested Kim date one of her sons. 04 of 15 SPY GAMES Peter Kramer/AP Naomi Watts and Liev Schreiber enjoy a night at the movies during the Cinema Society screening of Watts's fact-based spy drama, Fair Game, at New York's Museum of Modern Art on Wednesday. 05 of 15 CROWD PLEASER Florian Seefried/Getty After visiting Germany earlier in the week, Katy Perry heads to Austria Wednesday, where she performed at Vienna's Arena Wien. "Thank you Vienna, you were a lovely and very chic crowd," she Tweeted. 06 of 15 'OMG' MOMENT Anita Bugge/WireImage Guten Tag! A shaded Usher greets fans at a photo call in Berlin, Germany, where he promoted his upcoming OMG Tour on Wednesday. 07 of 15 SALES CALL INF Look who's getting a caffeine boost! With her drink in hand, Britney Spears gets ready for a day of shopping in Los Angeles on Wednesday. 08 of 15 RIDE ON Anthony Dixon/WENN You never know who you'll bump into on the MTA! Tyra Banks and Clay Aiken keep each other company Wednesday while taking the subway in New York. 09 of 15 BUST A MOVE Flynet Shake it! Reese Witherspoon lets loose Wednesday while listening to music on the Vancouver set of her latest film, This Means War. 10 of 15 COUTURE COUPLE Flynet Proving there's no better accessory than a dapper date, Rihanna brings boyfriend Matt Kemp to the Miu Miu ready-to-wear show Wednesday during Paris Fashion Week. 11 of 15 HOP TO IT Doug Meszler/Splash News Online Rachael Ray and husband John Cusimano get in the Halloween spirit Wednesday, dressing as Jessica and Roger Rabbit on the streets of New York for a segment on The Rachael Ray Show. 12 of 15 POOCH'S POSE Albert Michael/Startraks Hold that shot! Blake Lively channels her inner pup-parazzi Wednesday while capturing a furry friend on the set of Gossip Girl in New York. 13 of 15 IN A STRUT Xposure Victoria Beckham throws business casual out the window on Wednesday, strutting to work in fierce leather and studded platform heels in London. 14 of 15 WHEEL-Y FUN Mark Sullivan/WireImage Vroom! Gavin Rossdale joins elementary school students Wednesday for a test run of the new Hot Wheels cars in Los Angeles. 15 of 15 TRUE GLOVE National Photo Group What's black, white and checked all over? A gloved-up Brody Jenner and Avril Lavigne, making a monochromatic pair as they head into L.A.'s Premiere nightclub Tuesday night.