It's a Boy Girl Thing (2006)

Meet Nell (Samaire Armstrong) and Woody (Kevin Zegers), neighbors, classmates, and teen rivals. After a heated argument in front of an Aztec statue, the two awake to find themselves swapped bodies. Whereas their bodies are still with their respective families, the mind inside the bodies have switched. Now that Nell is in Woody and Woody is Nell, practical issues arise almost immediately, and more and more problems have to be solved daily, from hygiene, what to wear to school, guy talk, appreciating poetry, to how to talk to each other's friends and family. It did not take long for the two to also realize that this is their best chance to sabotage the other's image...