Pretty soon, we might be calling Oct. 31 Hollyween instead of Halloween.

Manufacturers and retailers predict this year's top costumes will be inspired by the same Hollywood characters that dominated screens.

The National Retail Federation picks princesses and pirates, often of the Disney variety, and Spider-Man to be the top children's costumes of the year, while Yahoo! Shopping adds "Star Wars," "Hannah Montana" and "High School Musical" as favorites with trick-or-treaters.

"Sometimes I feel I'm either on Wall Street or a movie mogul, I pay such attention to the box office," says Mary Ellen Turner, Party City's divisional vice president of seasonal departments — the company's "queen of Halloween."

At Party City, "Transformers" and "Hannah Montana" costumes are on top, while Amazon.com's Halloween store suggests "Harry Potter," "Shrek" and "High School Musical."

And it's not just movies — the big names in toys are another source of costume inspiration. Barbie-themed costumes are consistent performers and Transformers were in toy chests before they stormed the movie industry, notes Mark Randall, vice president of toys and baby products for Amazon.com. Randall will be looking at the fall 2008 toys next week for inspiration for next year's costumes.

"A licensed character is a powerful engine, whether it starts with a DVD, a Saturday morning cartoon, a network or a book like 'Narnia' or 'Harry Potter,' " agrees Turner. "They're such powerful influencers for children and, quite frankly, adults, too."

The adult-costume business gets bigger each year at Party City, according to Turner, and even adults aren't immune from the lure of Hollywood.

Costumes mimicking "Reno 911" rank as one of their top sellers with men this year.

The gory movie "300" wasn't really on the radar this past spring, Turner recalls, but she saw the marketing barometer begin to move, and Party City called its costume supplier long before it became a sleeper hit. The same thing happened last year for "V for Vendetta," she recalls.