A hit in the teenage gross-out genre, revived two years ago by There's Something About Mary, Road Trip reveals that director Todd Phillips knows exactly how far he can push the limits of decency before his film is sealed with an 18 rating.

One of the many rivals for the 'funniest scene' label is a sequence set in a sperm bank, in which an alarmingly aggressive nurse helps an unsuspecting young man (Scott) discover the amazing potential of his nether parts.

In fact, it's harder than you might think to choose a favourite bit in a movie that includes such farce as a full-figured female's seduction of a skinny-as-a-rake male virgin and the gratuitous theft of a bus from a school for the blind.

And as comical as it appears, with its clashing body types, the sex scene has an underlying sweetness. His sexual initiation transforms the movie's nine-stone weakling into a psychic he-man who musters the courage to stand up to his bullying dad.

Most of Road Trip follows the desperate cross-country dash of Josh (Meyer) and three fellow students to intercept a pornographic home video accidentally mailed to his long-distance girlfriend.

Thankfully though, there's more to Road Trip than just grossness. For, unlike There's Something About Mary, which was pretty flat when it wasn't being all-out hilarious, this effort remains funny throughout with more laugh-out-loud moments than would be possible to recount.

What's more, the dialogue is crisp, the pace is good, the scenery's pretty and an hour and a half with this kind of crew is enlightening and entertaining.

Dominic Bloch