Heidi Klum has just signed on to be a fourth judge on America's Got Talent!

AGT hot mama of 4 and model in a last minute negotiation and Heidi hopped on a plane to New Orleans over the weekend where the show is holding its first audition rounds!!

Heidi joins other AGT judges Howie Mandel, Howard Stern and new-comer Mel B. after Sharon Osbourne quit the show at the end of last season.