Mariah Carey & Nick Cannon arrived at a Halloween Party on the back of a fire engine… That’s hot.  Mariah apparently couldn’t decide what to dress as, so she went from fire girl to Famous Amos cookie girl over the course of the night… either that or she has a twin?

Tons of pictures of celebs at various parties/trick or treating… Check them out – just click on the first picture and then scroll through them.  Kimberly Stewart attempted to go as Britney Spears… so lame.  As if Kim is anyone to make fun of anyone else.  She looks more like Katie Holmes than Britney anyway!!

Photos: Splash News Online