Mandy Moore plays Anna Foster (codenamed "Liberty" by the Secret Service people who have to keep her safe), daughter to the president of the U.S.A. At the age of 18, she wants to be out doing stuff and dating boys, but crowds of Secret Service people around her make a normal life difficult. In Prague she makes a break for it, on the back of a scooter driven by Ben (Matthew Goode), who we shortly find out is also Secret Service (although she doesn't know it). Her father thinks this is a good arrangement, and makes Ben escort her on her further adventures.
I'll never know if I would have spotted that this was a riff on "Roman Holiday" - I was informed by Wikipedia before I saw the movie. "Roman Holiday" is quite possibly the best rom com ever made, so I thought I'd give this one a shot. Unfortunately, Moore's skills don't extend beyond "cute." Goode is incredibly handsome, charming, charismatic, and a better actor than Moore. He doesn't quite make it into Gregory Peck territory, but Moore is so far from Audrey Hepburn they couldn't see each other with telescopes. The silly and sloppy script is the nail in the coffin, and riffing on "Amélie" with the scooter scenes didn't particularly help. Mildly amusing at best.