Songfacts®:

• This tale of a crazy road trip with friends was written by Katy Perry together with Desmond Child ("You Give Love A Bad Name," "Who Let The Dogs Out") and the Swedish songwriter and producer Andreas Carlsson ("I Want It That Way," "That's The Way It Is").
  
  Desmond Child told Songfacts how the song came together for Perry: "At that point when I met her she was between record deals. Then she got one at Columbia Records and then she was dropped from there and she went to the next thing. And that song managed to survive all of those changes. It came out as the fourth single of her first record at Capitol, and it went to #1 (on the Dance and Pop Songs charts). That was like five, six years after we had written it.
  
  I knew it was strong, but it took her personality and an accumulation of other hits before that one to put it over the top. And the song is great. I've heard it done by Country groups. The song adapts to different styles. So that's always a good sign of something that could have potential. And maybe the really big hit of that hasn't even appeared yet. Could be 20 years later, like 'Lady Marmalade' was for Bob Crewe."
• Perry explained this song to The Sun September 26, 2008: "Vegas gives me that 'what the f--k feeling.' It's really close to LA so one night you could be having a beer with your friends and, when you wake up, you're in Vegas." She describes Vegas as "an iconic place where lots of trouble goes down," and adds, "it's a fun song about getting into trouble and not regretting it."
• This was Perry's first single release for which she was credited as a co-producer. The other co-producer, Greg Wells ("Ur So Gay," "I Do Not Hook Up"), is credited with playing all of the instruments on the song.
• The song's music video was directed by Joseph Kahn, who also helmed Britney Spears' "Toxic" and The Pussycat Dolls' "When I Grow Up." In the clip, which was filmed in Las Vegas, Perry kisses a boy. Her love interest is played by the actor Joel David Moore (Bones, Avatar). The car featured in the video is a Lamborghini Murciélago.
• This song topped the Pop Songs/Mainstream Top 40 radio chart. It was the first chart-topper since the tally's 1992 launch to reference a city in its title.