Hollywood will be vying with itself this weekend when four new films compete with the Oscars for moviegoers' attention. In fact, according to box-office analysts, it's likely that all four movies will take a back seat to last week's top films, Ghost Rider and Bridge to Terabithia. The latest crop is led by The Number 23, a thriller starring Jim Carrey in a serious role, his first since 2004's Eternal Sunshine of the Spotless Mind. The weekend will also see whether the "viral" marketing campaign for Reno 911!: Miami, based on the Comedy Central series, will pay off. Warner Bros. will be offering The Astronaut Farmer, about an astronaut who tries to build a rocket on the family farm, while Amazing Grace, a historical drama about the efforts of Britain's William Wilberforce to end slavery, opens in a more limited release,