The White House Correspondents' Association dinner is tonight, and it's the perfect mix of self-congratulation, celebrity-worship and Justin Bieber. Everyone's already there, here are some things from their twitter accounts. (You can watch live coverage here.)

Sen. Scott Brown arrived in his pickup! (via someone)

Observer Reporter John Kolbin was impressed by the size and security! (via John Kolbin)

Talking Points Memo Reporter Christina Bellatoni was shot down by Zach Galifianakis! Probably because she spelled his name wrong! (via Christina Bellatoni)

Justin Bieber arrived!

And there is famous person Kim Kardashian!

And here's your host, Jay Leno!
(via CNN's Ed Henry)

This guy got his picture taken with Zach Galifianakis! (via some guy)