Ryan Reynolds flashed his charming smile as he strolled through a very sunny NYC on Friday. Ryan and girlfriend Blake Lively are both on the East Coast while she is working on her final season of Gossip Girl. Blake and Ryan live together outside the city and spent the early part of July in upstate New York for the Fourth of July week. Blake wore a bikini while Ryan went shirtless for one outing and the two snuck in sweet kisses and PDA at a family picnic. Blake and Ryan are coming up on their first anniversary in a couple months, though they may be at odds over the coming weeks. All-American Blake and Canadian-born Ryan may be rooting for different teams in the London Olympics — check out the other countries stars come from!

Katie Holmes gave a friendly goodbye kiss on the cheek to the guy friend she had dinner with on Friday night in NYC. Katie was glowing and smiley after the adults-only night out on the town. Katie and Suri took a trip to Toledo, OH, to visit family last week, but otherwise, the mother-daughter duo have been spending most of their time in the Big Apple. Katie was scheduled to help host her annual Dizzy Feet Foundation event this evening in LA, though she announced on Friday that she would not attend. It would have been her first red carpet appearance since her divorce from Tom Cruise. The actress is not avoiding the spotlight for long, however, since Katie's returning to Broadway this Fall in a production of Dead Accounts. Katie has yet to announce any new big-screen projects.

Gwen Stefani took her sons Kingston and Zuma to check out the rides in Central Park in NYC on Friday. Zuma beat the heat by taking off his shirt to check out the swings. Gwen treated Kingston and Zuma to Popsicles to cap off their Summer afternoon in the big city. Kingston was showing off some blue hair earlier in the week, though it looks like the dye job was only temporary. Gwen is in New York to promote the new No Doubt album, Push and Shove, which will be released in September. No Doubt performed their new single, "Settle Down," on Good Morning America on Friday, and we'll be seeing a lot more of Gwen and her bandmates as they promote their first release as a band in 10 years.

Katy Perry wore a bikini to lounge by the pool with friends, sip drinks, check her iPhone, and work on her tan in Miami on Friday. She has been in Florida for a few days. Katy was spotted reading Robert Pattinson's BlackBook issue during another poolside afternoon earlier this week. Katy is not among the many celebrities who commented publicly about the Kristen Stewart cheating scandal, though she is good friends with both Robert and Kristen. Katy's own love life is back in the headlines as well, since she was reportedly spotted getting close to John Mayer recently in LA.

Celebrities had a busy week filming, celebrating birthdays, and enjoying London before the Olympics. Jennifer Aniston was on the set of her latest movie, We're the Millers, in Wilmington, NC, while Rihanna showed off her bikini body near Saint-Tropez. Jennifer Lopez wore a hot red dress for her birthday celebrations in NYC, and the Beckhams enjoyed a pre-Olympics lunch date with baby Harper in London.

Much more went down with the stars this week. Click through for the rest of the exciting pictures.