After being treated for dehydration, Richie heads out to dinner with beau Joel Madden in Beverly Hills. Plus: Madonna & Guy, Tom & Katie and more

HIS NAME IS...

In case there is any doubt who's headlining this party, Kevin Federline shows off his top billing at The Beatles Revolution Lounge in the Mirage Hotel & Casino in Las Vegas on Sunday. It's a rare appearance for the aspiring rapper, who has been in daddy mode with sons Sean Preston, 18 months, and Jayden James, 6 months, since estranged wife Britney Spears checked into rehab.