"The clenching of the buttocks is something I've practiced and auditioned many a year," London-based actor Rhys Ifans, 31, says of the sequence in which he poses bodybuilder-style for a swarm of paparazzi chasing Roberts' famous movie star. "To actually do it on screen and get paid for it is a dream."

Meet the congenial chap behind Spike, a prime specimen of the universal nightmare known as the roommate from hell. Filthy feet. Lewd T-shirts. An inability to write down phone messages, toss out crusty pizza boxes or distinguish mayonnaise from yogurt gone bad. As (Hugh) Grant says of the human mess who shares his flat, "There's no excuse for him."

The Welsh-born performer (whose name is pronounced "Reese E-vens"), the son of schoolteachers, has appeared in several films, most notably Dancing at Lughnasa with Meryl Streep and Twin Town with his brother, Llyr. But it was his work in a stage production of Dylan Thomas' Under Milk Wood, directed by Notting Hill's Roger Michell, that earned him the audition for the role of Spike.