HEDI KLUM IS AMERICA'S GOT TALENT 4TH JUDGE

And the checks just keep on coming in, Project Runway host has made "America's Got Talent" a little hotter ... because TMZ has learned Heidi Klum has just signed on to be a fourth judge on the reality TV show ... which begins taping tomorrow.

Sources close to NBC tell TMZ that "AGT" scored Hedi in a last minute negotiation and Heidi hopped on a plane to New Orleans today ... where the show is holding its first audition rounds. 

TMZ obtained a photo of the "AGT" set taken today ... which clearly displays the name "HEIDI" underneath her own personal judge's "X" ... which she'll use to crush people's dreams.  

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

Video: Mariah Carey Performs on ‘America’s Got Talent’ Squeezes Hubby Butt!!

Mariah Carey performed her single “Obsessed” for the first time on TV on Wednesday’s episode of her husbands gig “America’s Got Talent” hosted by Nick Cannon. The end of the Video makes up for her lackluster performance.

Mariah with her around the way hair do and stiff moves lip syncing , the best part about this performance was those shoes she couldn't walk in and her playful interaction with her Hubby Nick Cannon at the end she squeezes his BUTT, showing how she really feels about her Boo. SO CUTE!!