Melbourne is on the verge of an international invasion, both on and off the track, as the spring racing carnival gets into full swing.

This year's star attractions off the track include Hollywood actress Kate Bosworth, who will be a guest of Motorola on Derby Day.

Bosworth, star of Superman Returns, is expected to judge the Myer Fashions on the Field competition and attend Motorola's VIP marquee in the Birdcage.

Local designers are clamouring to dress the tiny star. Sass & Bide, Willow, Alex Perry and Collette Dinnigan are among designers asked to send garments to Los Angeles for Bosworth to sample.

Other stars at this year's carnival include actor Michael Vartan, of Alias fame; Backstreet Boy Nick Carter and his younger, pop singer brother, Aaron; Diana Ross, who will perform at the VRC's chairman's dinner on November 1; and Chris Isaak, who will perform at various events at the carnival.

One of the most glamorous women at the track this carnival will be little-known Francesca Cumani, 23, a part-time model and ex-jockey turned strapper, who is the daughter of English trainer Luca Cumani, who has brought out Cup contenders Glistening and Soulacroix.

Cumani, who won two races as a jockey in Britain, was the face of England's Vodafone Derby this year.

She and her father are determined to take the Melbourne Cup back to Britain.

She says modelling is "fun to do occasionally" but thoroughbreds take centre stage in her life.

"I was riding before I could walk," Cumani says. "I loved horses from the word go."