Why do they do it? They can earn millions per movie but some film stars are still stage-struck, eager to tread the boards at union minimum for the sake of art. Or they're past their Hollywood prime and return to the stage in some creaky star vehicle. Elizabeth Taylor in Little Foxes anyone? Joan Collins got away withPrivate Lives in the West End, but Charlton Heston's nest of wigs in A Man for All Seasons was more memorable than his performance. (Rumour has it he kept on his own toupe, so the wig for the part perched on top of it every night.) Lauren Bacall had a major success with Applause on Broadway. Even more successful, when she took time off, was her successor - a certain Raquel Welch.

Theatre-trained actors can usually cope. Anthony Hopkins returned from his first Hollywood sojourn in the Eighties to give a towering performance in Pravda. In America Glenn Close has succeeded both in straight drama and Lloyd Webber's Sunset Boulevard. Less successful was ex-model Faye Dunaway, who famously parted company with the Lloyd Webber production.

Jessica Lange, an Oscar winner, suffered at the hands of the critics for her part on stage as Blanche Dubois in a Broadway revival of A Streetcar Named Desire. Her co-star, Alec Baldwin, on the other hand, movie star husband of Kim Basinger, was given the kind of adulation that Brando himself received over 30 years before as Stanley Kowalski.

Al Pacino has played memorably in David Mamet plays both here and on Broadway. Ralph Fiennes's Hamlet suffered from the audience being unable to see the eyes that shone so brightly on the silver screen. Dustin Hoffman gave a creditable performance as Shylock in the National Theatre's production of The Merchant of Venice. Richard Gere, early in his career, took time off to appear in an acclaimed stage version of Bent.

The theatre and the movies require different acting. Some performers find it hard to make the adjustment. The most surprising people don't. It's often forgotten that Humphrey Bogart, Hollywood star par excellence, was a classically trained actor who spent years in the theatre before making the move into films.