From MSN Scary Celebs
http://movies.msn.com/movies/scarycelebs?photoidx=1
From coast to coast, Halloween has already been merchandised into one of the biggest of holiday cash cows. But the revelry associated with October 31 achieves a unique fever pitch in Hollywood, Soho, Vegas or wherever show biz kids gather when they're not on the set, in the studio or otherwise earning their keep. Here's a cavalcade of celebrities dressing up to trick or treat in all the fashionable places.
MARIAH CAREY
The pop diva steps out at her own 2003 Halloween party in New York's Chelsea neighborhood, adapting her usual fondness for décolletage with clamshells that we're guessing pay homage to the Little Mermaid ... with (what else) glitter!
That's Sandra Bullock, fur sure, sporting a different kind of teddy with then-beau Jesse James at a Hollywood Halloween bash during their courtship.

Martha Stewart hangs ten at
Bette Midler's 1998 Halloween bash at New York's Waldorf=Astoria
She may have graduated to an evening anchor desk, but will Katie Couric miss the chance to get her glamour on? Here she replaces perky with va-va-voom as she morphs into
Marilyn Monroe for the 2004 "Today" Halloween special.
Bette Midler brings glamour to the nurse's station while Rosie O'Donnell adds a mad gleam to her bedside manner at Midler's 1998 Halloween bash at New York's Waldorf=Astoria.
Ingenue Anne Hathaway abandons her usually demure look to vamp it up, Egyptian style, at
Heidi Klum's 5th annual Halloween party in New York in 2004.

O, the places he could go: Al Roker jumps into
Oprah's shoes for the 2004 "Today" Halloween special.
Ice-T deserts his "
Law & Order: SVU" TV persona to resurrect his gangsta origins (albeit as a crook with bad luck), guarded by pneumatic cop-for-a-night CoCo, at
Heidi Klum's 5th annual Halloween party in New York in 2004.