First of all, let's get the inevitable comparison with fellow diva vehicle, Glitter, out of the way: this isn't as bad. While she's no natural, Spears (unlike Mariah Carey) looks acceptable on the big screen - thanks chiefly to the amount of taut, tanned flesh the plot contrives to make her display. There are even moments of intentional humour.
Unfortunately, the crux of the film is an uneventful road trip, and subplots - such as Lucy's reunion with her mother (Kim Cattrall) - are lost before they get the chance to involve.
Even for a teen movie, the characters lack depth, especially Spears' saccharine Miss Perfect, whose romantic and musical success is so inevitable, any potential tension is lost. Although, ironically, the poetry-put-to-song moment that will have adults reaching for the sick bags may be the very point at which aspirational Britney fans are won over.