Zach Galifianakis

London got a large dose of star power today when the cast of The Hangover hit the red carpet to premiere the third installment of their franchise. Bradley Cooper, Justin Bartha, Ed Helms, Zach Galifianakis, Todd Phillips, Ken Jeong, and Heather Graham met up in front of the cameras to pose for pictures and chat among themselves, flashing plenty of smiles along the way. It was their second big event of the week after also bringing the movie to LA on Monday. It looked like Zach was on his best behavior in the UK following his funny antics at the West Coast premiere — Zach hopped into a car trunk before walking the carpet with his formerly homeless friend, Mimi Haist.

The promotions will continue for the gang in the run up to their film's Friday premiere. Make sure to check out our review of The Hangover Part III before you head to the theater this weekend!

It was a wild reunion for the cast of The Hangover at the premiere of the franchise's third installment in LA last night. Bradley Cooper broke from the NYC set of American Hustle to attend the big event alongside Ed Helms, and Zach Galifianakis. Newly-engaged member of the crew, Justin Bartha, was also on hand for the night of fun. The guys showed love for their costar Ken Jeong and the waiting fans, many of whom Bradley stopped to snap pictures with before heading into the screening. The ladies of the Hangover trilogy, including Heather Graham, Sasha Barrese, Gillian Vigman, and Jamie Chung all hit the red carpet as well to celebrate the film's Friday release. It'll be the first big holiday-weekend Summer movie matchup, since Fast & Furious 6 also hits theaters. If you can't decide which sequel to spend your money on, these pictures of Bradley Cooper looking hot in the Hangover Part III might help!

Bradley Cooper and his The Hangover Part II castmates Ed Helms, Zach Galifianakis, Justin Bartha, and Jamie Chung greeted fans at last night's Berlin premiere. The sequel, which hits theaters today, throws the wolf pack back into familiar circumstances after another bachelor party goes awry — read The Hangover Part II reviews to see what critics think of how the new installment compares to part one. The stars and director Todd Phillips had their first screening event last week on the West Coast, and made a stop in NYC for another showing earlier this week. Bradley managed to swing by SNL during his stay in the Big Apple, and joined host Justin Timberlake for the afterparty with Olivia Wilde. Bradley and Olivia were spotted sharing an intimate chat during the soiree, fueling rumors that they're dating.

The Hangover Part II is out this week, and Warner Bros. has released these of one-sheets featuring the famous Wolfpack. The banners are strikingly similar to the posters that were released to promote the first movie, which doesn't come as a surprise considering the trailer for The Hangover Part II seems to be following the original formula pretty closely. Still, it's fun to compare and contrast, so check out how the guys look then and now!

The cast of The Hangover Part II got together with their director, Todd Phillips, for a screening of the comedy in NYC yesterday. Bradley Cooper, Ed Helms, and Zach Galifianakis made the trip east following the premiere of their film in LA last week, and they kept the fun coming with an afterparty at the Top of the Standard. Something Borrowed's Colin Egglesfield was there to show his support as was a pregnant Ivanka Trump, who tweeted that the movie was "hilarious." Also on hand were Victoria's Secret models Alessandra Ambrosio and Selita Ebanks, enjoying a funny break from their recent press for the lingerie brand. The sequel comes out on Friday, just in time for Memorial Day weekend, and early The Hangover Part II reviews seem to suggest that it's worth taking a trip to the theater between your BBQs and beach games.

The many men of The Hangover Part II gathered at Grauman's Chinese Theatre last night for their big LA premiere. Bradley Cooper was dapper in a Tom Ford suit and flashed a big smile for photographers next to his costars Zach Galifianakis and Ed Helms — they even had Crystal the Monkey there! Ken Jeong was one of the first down the carpet, and he spoke to us about his excitement at reuniting with the guys. He even admitted to being open to expanding his Mr. Chow character in a possible spinoff. Ken, who's actually an MD in real life, said his medical knowledge came in handy when some of his castmates came down with food poising while they filmed in Thailand! Ed Helms was likewise thrilled to get a meatier part in the sequel. His small-screen project, The Office, aired its season finale yesterday, and Ed revealed that he doesn't know what's next, but Steve Carell's rumored replacement, Catherine Tate, is a pro. The screening brought out plenty of famous faces, like cute couple Kristen Bell and Dax Shephard, Mike Tyson, and a super-pregnant Alyssa Milano. Kristen and Crystal shared an especially intimate moment. Stay tuned for more on today's PopSugar Rush!